Relative Humidity Isn't What You Think It Is

Рет қаралды 334,811

Күн бұрын

This episode is brought to you by the Music for Scientists album! Stream the album on major music services here: streamlink.to/music-for-scien.... Check out “Aristarchus in the Rain” here: • Aristarchus in the Rain
Have you ever wondered why 75% humidity in the summer feels sticky, but 75% humidity in the winter feels super dry? Turns out, the common definition of humidity is inconvenient and confusing. But there is a better way!
Hosted by: Michael Aranda
SciShow has a spinoff podcast! It's called SciShow Tangents. Check it out at www.scishowtangents.org
----------
Support SciShow by becoming a patron on Patreon: / scishow
----------
Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever:
Silas Emrys, Drew Hart, Jeffrey Mckishen, James Knight, Christoph Schwanke, Jacob, Matt Curls, Christopher R Boucher, Eric Jensen, Adam Brainard, Nazara, Growing Violet, Ash, Laura Sanborn, Sam Lutfi, Piya Shedden, Katie Marie Magnone, Scott Satovsky Jr, charles george, Alex Hackman, Chris Peters, Kevin Bealer, Alisa Sherbow
----------
Looking for SciShow elsewhere on the internet?
Facebook: / scishow
Twitter: / scishow
Tumblr: / scishow
Instagram: / thescishow
----------
Sources:
www.washingtonpost.com/news/c...
voices.washingtonpost.com/capi...
www.weather.gov/lmk/humidity
howthingsfly.si.edu/ask-an-ex...
www.researchgate.net/profile/...
Image Sources:
commons.wikimedia.org/wiki/Fi...
commons.wikimedia.org/wiki/Fi...

Пікірлер: 695

@SciShow 3 жыл бұрын

This episode is brought to you by the Music for Scientists album! Stream the album on major music services here: streamlink.to/music-for-scientists - Check out “Aristarchus in the Rain” here: kzfaq.info/get/bejne/odt0aZSKqdPaZok.html

@jarnomikkola8438 3 жыл бұрын

I applause your use of the reverse centergade scale.

@gehteuchnichtsan7911 3 жыл бұрын

The album title and artwork looked really promising but the music is not my taste sadly. The lyrics are scientifically correct thou. ✌️👌

@ThatChemistOld 3 жыл бұрын

it isn't good music and I am a scientist so this is not music for all scientists

@LastTruth1 3 жыл бұрын

I tried to listen to music for scientist. And i couldn't.. its horrid

@TUnmitigatedGall 3 жыл бұрын

@47f0 3 жыл бұрын

Here in central Florida, the only reason we don't hit 100% humidity is because the mosquitoes are taking up too much space that water molecules might otherwise occupy.

@IHateUniqueUsernames 3 жыл бұрын

Good one!

@virglibrsaglove 3 жыл бұрын

🤣🤣🤣🤣🤣

@iafozzac 3 жыл бұрын

100% humidity just means that fog starts forming

@blazedgamingkr1438 3 жыл бұрын

🤣🤣🤣

@AbsintheRed2019 3 жыл бұрын

It’s the same here along the Texas coast.

@TheZenytram 3 жыл бұрын

as a child i thought that 100% humidity would be full of water so we could swim in the sky.

@itsthevoiceman 3 жыл бұрын

Hollywood would do well to make skits based on children's fantasies.

@LuisAldamiz 3 жыл бұрын

It's so obvious, ain't it?

@joanhoffman3702 3 жыл бұрын

I like the way you think.

@nielsdaemen 3 жыл бұрын

That's what I thougth as a child too😄 In reality even at a dewpoint of 20°C the humidity ratio is just 1.5% water in the air

@xxmountaindewxx7893 3 жыл бұрын

Same

@Qui-9 3 жыл бұрын

Another explanation not mentioned here, about why skin feels dry on a cold, humid day, is 𝙩𝙝𝙖𝙩 air gets warmer next to the skin or by the building we're in, so it's now relatively dry. That's why indoor humidifiers are handy in cold seasons. Precipitation happens for the opposite reason. It can be analogous to a soaked sponge which is squeezed when it's cold and released when it's warm.

@AileTheAlien 3 жыл бұрын

Luckily for me, I prefer drier air, so winter is great for me...except for the cold...and the shovelling... :)

@MegaBrokenstar 3 жыл бұрын

The one thing you’ve got to consider in the winter is that, unless your walls use thermos technology, there’s always air exchange between the inside of the walls and the outside. What that ends up meaning is that if you humidify the air *too* much, then when that air gets inside the exterior walls and perfuses through the insulation, it will still be full of that humidity when it comes into contact with the much, MUCH colder outer side of the exterior walls. This can unfortunately tend to cause water to condense and build up inside the walls, leading to water damage, rot, and mold. You might’ve seen an extension of this effect if you’ve ever had an absurdly, like -10 to -15°F or lower, cold morning where you live and woken up to find your multi-pane, usually draftless windows partially coated with a layer of frost on the inside.

@mikefochtman7164 3 жыл бұрын

@@MegaBrokenstar And that is a key to the use of vapor barriers. In climates that get cold, it is important to use a vapor barrier on the INSIDE of the insulation (not breathable 'house wrap'). This helps prevent the humid air inside finding it's way through that insulation and doing just as you said. But in muggy climates (think Gulf Coast of US in july), the opposite happens and you the same problem in reverse.

@tippib2222 3 жыл бұрын

I just go by how big and frizzy my hair is. “Hmm... my hair is smooth, yet not staticky. The humidity is juuuuust right.”

@virglibrsaglove 3 жыл бұрын

You and me both! 🤣🤣🤣

@theblinkingbrownie4654 3 жыл бұрын

I go by how sticky my skin feels, I wash myself so many times oof

@xeth9074 3 жыл бұрын

Living humidity detector.... I needs one... Become my neighbor plz... you may assist me in this humidity problem.

@Jemima1377 3 жыл бұрын

Well, your hair IS essentially a hygrometer! ^_^ A lot of the old ones work exactly like that: there is a hair in the meter and depending on the humidity in the water, it expands or tigthens on a coil - which you can read as a measurement and if calibrated correctly gives you an old-school hygrometer...

@Tommy_Mac 3 жыл бұрын

I used to do that. Now that I'm bald, I look for sweat running down.

@why_though 3 жыл бұрын

Engineers around the world: "Where's the catch? You just recited the definition..."

@SelectHawk 3 жыл бұрын

Yep. Probably scientists, too. A bit disappointing, because I usually still learn something new from these videos.

@emmettturner9452 3 жыл бұрын

Exactly. I’m all like, “uhhh, isn’t that what ‘humidity’ has always meant?!”

@Kamel419 3 жыл бұрын

yea, i was really expecting to be surprised with this one lol.

@Chlorate299 3 жыл бұрын

You got me! The key term is "relative".

@zanaster8438 3 жыл бұрын

Oh the basics to thermodynamics... oh the horrors of that class

@DaveSomething 3 жыл бұрын

Relative Humidity is EXACTLY what I thought it was!

@mastaw 3 жыл бұрын

Same lol

@titaniumjackal 3 жыл бұрын

Clickbait title.

@davidsellon4580 3 жыл бұрын

since 5th grade.

@Qui-9 3 жыл бұрын

Titaniumjackal not really clickbait. Look around and the world is full of people who don't understand some basic science. I knew what the video was going to get at and I still enjoyed the explanation.

@DaveSomething 3 жыл бұрын

@@Qui-9 exactly

@jeff__w 3 жыл бұрын

In 1939, actor Peter Lorre played the lead in a movie titled _Mr. Moto on Danger Island._ At the end of the picture, an actor named Warren Hymer spoke the line, “It’s not the heat, it’s the humidity.” People have been saying it ever since.

@D-Vinko 3 жыл бұрын

Thanks peter, you confused everyone.

@icarlyIV 3 жыл бұрын

Something every midwesterner says lol

@patrickmccurry1563 3 жыл бұрын

It is literally true though. Really low humidity and I was fine on a long walk in 105 F. But I have sweat my guts out with moderate humidity in the 80s.

@jeff__w 3 жыл бұрын

@@patrickmccurry1563 “It is literally true though.” Sure, that’s why people have said it since 1939. It definitely rings true.

@sheldonwheaton881 3 жыл бұрын

Down here in Florida, they go by dewpoint. Humidity is rarely mentioned.🗿🌴

@k1dicarus 3 жыл бұрын

Fighting the good fight.

@HweolRidda 3 жыл бұрын

Dew point is humidity. You mean relative humidity, as the video discusses. Quibbling aside, good job Florida.

@travcollier 3 жыл бұрын

Due point is commonly reported lots of places. Also, the humidity measures you see in a weather report are typically derived from the difference between wet-bulb and dry-bulb temperatures. That's the old fashioned and in most ways still best way of doing it. So... This video is the rare fail from SciShow IMO. PS: That said, digital RH sensors are super convenient. SHT31 is my favorite.

@kyleellis9177 3 жыл бұрын

Florida isn't real. It's a rumor made up to scare children, same as Australia.

@CrimsonSwitz 2 жыл бұрын

@@k1dicarus aopwwss

@cornbreadfedkirkpatrick9647 3 жыл бұрын

Live in the southern part of the USA you'll learn this real fast during the summer until September the latest

@MistSquid 3 жыл бұрын

You aint lying bow

@LawTaranis 3 жыл бұрын

Try in north Dakota. It gets almost as humid as houston in some places (not as hot most of the time, though!) And I'm the winter we regularly see temperatures in the double digits below 0. The apparent humidity is WILD

@cornbreadfedkirkpatrick9647 3 жыл бұрын

@@LawTaranis Houston is a dry heat Alabama is a wet heat wanna trade, well I think about that either, about that It does snow some here when I was growing up it dumped a load of snow in May, yeah but it hasn't done a repeat

@georgestgeorge5110 3 жыл бұрын

Basic training at Ft. Jackson. Humidity is REAL. Like trying to run at the bottom of a pool.

@cornbreadfedkirkpatrick9647 3 жыл бұрын

@@georgestgeorge5110 I believe you

@christelheadington1136 3 жыл бұрын

"Relative Humidity Isn't What You Think It Is" You mean it doesn't mean my siblings are all wet ?

@9051team 3 жыл бұрын

obligatory 'what are you doing step bro?' comment here.

@ThePowerLover 3 жыл бұрын

@@9051team Wut?!

@k1dicarus 3 жыл бұрын

@@9051team step bro, im so relative humid, can you help me please?

@brushboss99 3 жыл бұрын

@@ThePowerLover ?

@TragoudistrosMPH 3 жыл бұрын

*envisions summer days with super soakers* 😁

@collinbarker 3 жыл бұрын

If you like another method of findingout what the temperature "feels" like, Humidex is used in Canada quite frequently. Similar to wind chill, it uses the temperature and relative humidity to state what the temperature "feels like" to a regular person. It might be only 31°C, but it will feel like 38° with 55% humidity. It takes into account the fact that the air cannot pull your sweat off. Wind chill is the same, but uses wind speed and temperature instead, and is used for cold weather

@MarcelaElviraTimis 3 жыл бұрын

I'm familiar with "perceived temperature"

@caterscarrots3407 3 жыл бұрын

I’m familiar with wind chill and heat index, but I know they have their limits. I have tried calculating heat index and wind chill and I get things like humidity lowering temperature and wind raising temperature, which happens in the real world every year, but breaks the limits of heat index and wind chill. One calculation I’ve done is wind chill for 80 degrees F and 60 mph winds and according to that, I get 82 degrees, an even warmer temperature. On the one hand, wind warming temperatures happens all the time. On the other hand, I’ve been in conditions close to that calculation and in my experience, 60 mph winds always give a chill regardless of whether it’s winter or summer weather. So, it would be nice if the meteorologists here in the USA extended the wind chill from a maximum of according to some sources 50 degrees F and according to other sources 70 degrees F to summer temperatures.

@SiqueScarface 3 жыл бұрын

As it turns out, relative humidity is exactly what I thought it to be. :)

@tedlis517 3 жыл бұрын

Yep, no surprises.

@kimberlyk2530 3 жыл бұрын

🤓👌🖕

@pedroarjona6996 3 жыл бұрын

My middle school science teacher seems to had been right on the spot.

@pedroff_1 3 жыл бұрын

I'd say the actual catch is that our body temperature (and, oftenx the temperature indoors) is mostly fixed, which makes the relative humidity of those places significantly lower than that of the environment if there's a big temperature gradient

@MegaBrokenstar 3 жыл бұрын

The fact that those temperatures are more consistent are big parts of why dewpoint is a much more useful metric.

@Kerbezena 3 жыл бұрын

I strongly believe that that is exactly what regular SciShow viewers thought relative humidity is.

@kennethtaylor6084 3 жыл бұрын

I don't know how many times I've explained this concept after learning it in one of my atmospheric science classes. My mind was blown when I finally understood this.

@noahway13 3 жыл бұрын

You are right. There is a difference between knowing and understanding...

@miriamrosemary9110 3 жыл бұрын

THANK YOU! Humidity percentages have confused me often... I had already learned about how it's relative to the amount of water the air can hold, but I didn't think about how that would change at different temperatures. Finally, an explanation for the lack of consistency between a percentage number and how humid/dry it feels...

@jon-michaelharris5840 3 жыл бұрын

As a Floridian, I am shocked that 68 degrees was a temperature that the writers thought was warm.... 68 is a pipe dream April through September

@D-Vinko 3 жыл бұрын

@@samarnadra High heat, low humidity. Everything dries out immediately. Higher heat = more potential water in the air, yet we have only 13% on good days, until monsoon. Jerky is easy to make though, just cut season hang and it's guaranteed to dry out fast.

@crazydrummer181 3 жыл бұрын

I’m in South MS and I know how bad an 88 degree day with 80% humidity is. The air is like hot soup.

@yetinother 3 жыл бұрын

68F is a nice balmy day where you can take both of your jackets off.

@JonathanMandrake 3 жыл бұрын

I always knew that fact. And, to some degree, both relative and absolute humidity are important.

@stevensines7026 7 ай бұрын

As a teen, I had an amateur weather station that I used to make my own weather reports. It included a pair of thermometers, one normal, one with a gauze "string" attached. This one was to be kept wet so that the difference in wet temp could be measured. Through the dual readings and a bit of simple math, the humidity could be determined. It wasn't rocket science, but it worked.

@edwardblair4096 7 ай бұрын

That is called a "wet bulb" temperature. It measures how much cooling you can get by evaporating water into the air. The wet bulb temperature is always between the dew point temperature and the "normal" air temperature. That is, it is impossible to cool air all the way down to the dew point temperature. Thiis also has a direct effect on how effective a "swamp cooler" is. In places with a high humidity, and therefore a high wet bulb temperature, evaporative cooling systems don't work.

@joann5051 5 ай бұрын

That's cool. What career path did you follow?😊

@PaulSteMarie 3 жыл бұрын

Dew point measurements are hardly new. All you need is a wet bulb thermometer, much less complicated than a hygrometer. It's just a regular old thermometer with a cotton wrap on the bulb that gets water put on it.

@davehaggerty3405 3 жыл бұрын

It is called a sling-thermometer. It is a thermometer in a cotton sling. You wet the sling then spin it around to achieve maximum evaporation to get an accurate reading.

@kellyrowland9470 3 жыл бұрын

This might be the most important SciShow ever for mushroom growers!🍄🍄🍄🌟

@LuisAldamiz 3 жыл бұрын

What's the ideal humidity for that? How much they pay for them?

@kellyrowland9470 3 жыл бұрын

@@LuisAldamiz depends on species but usually anywhere from 70-85% RH. Just depends on what your growing for exactly...

@LuisAldamiz 3 жыл бұрын

@@kellyrowland9470 - That's exactly the kind of humidity we have here year long (I just confirmed: hygrometers are of little use when they always read "high"). Nobody grows mushrooms that I know of however.

@LuisAldamiz 3 жыл бұрын

@@kellyrowland9470 - Can you grow Boletus edulis indoors? I guess not but it'd be great because it's a very expensive culinary mushroom.

@BronzeDragonWOHS 3 жыл бұрын

Thank you for including Fahrenheit references, makes it much easier for those of us who weren't blessed enough to grow up in a metric country. wish Sci Sho would do this with all of their vids.

@philophos 3 жыл бұрын

This is exactly what I thought relative humidity was, but this title convinced me I was wrong before I had even started.

@roberthobbs6318 3 жыл бұрын

I am born and raised in Calgary Canada, border line desert, it frequently gets to around -30°c in the winter, and when there is higher "humidity" at that temp it just means that there is going to be ice crystals floating around (yay sundogs!) but it's definitely still "dry". Not sure how relevant that is, but hey, gimme a soapbox and I will proclaim! Love the vids guys!

@AmyMcLean 3 жыл бұрын

I have a hygrometer in my kitchen that's been helping me keep my skin from cracking during the winter.

@madamsloth 3 жыл бұрын

I gotta get myself one! Didn’t know about these, thx for mentioning them

@uhohhotdog 3 жыл бұрын

Same. I know when i need to run my humidifier.

@AmyMcLean 3 жыл бұрын

@@madamsloth it's part of a big clock that was left in the house we bought a few years ago. Giant atomic wall clock with a thermometer and hygrometer. It's freaking awesome!

@virglibrsaglove 3 жыл бұрын

I have one, too in my bedroom. Mine has temperature and humidity. In the winter I run the humidifier. In the summer, the dehumidifier. The hygrometer helps me to know I'm not insane when it feels time to adjust the humidity.

@LuisAldamiz 3 жыл бұрын

Mine is no help: it always reads "high" and does nothing at all but sitting there all the year without giving any info or doing anything. Seriously: I've seen hygrometers since kid and always have the suspicion they are all broken because the needle doesn't even move (but then they never say "low", which would contradict the facts, so maybe they are working perfectly).

@walrus4046 3 жыл бұрын

I always thought that relative humidity was a measure of how angry our mom got at us kids. She could get really steamed up with us. Looking back I can't say I blame her! lol

@LuinTathren 3 жыл бұрын

You just won the Interwebs! What do you have to say?

@walrus4046 3 жыл бұрын

@@LuinTathren I would like to thank my mother and my brothers and sister without whom this award would not have been possible. I shall honour it and it is as much for them as it is for me. Thank you to all who voted Thank you and I love you all!

@F_L_U_X 3 жыл бұрын

All that just to laugh at the word 'steamed'? 😞

@Magic-Conk 3 жыл бұрын

Thank you for answering a question I've wondered so long.

@erickfrago7224 3 жыл бұрын

Hi Michael. Nice to see you again!

@briang5994 3 жыл бұрын

I was a crew chef on a helicopter. On some morning if you were the first in the air that day and it was really close to the dew point. You could look behind the aircraft and see the fog forming where we had just been. Was awesome

@michaeldamolsen 3 жыл бұрын

As I read this, I could hear flight of the Valkyries spinning up :)

@zperk13 3 жыл бұрын

thanks for the captions!

@Grim_Beard 3 жыл бұрын

Misleading title. Relative humidity is exactly what I thought it was.

@musashi939 3 жыл бұрын

In other news, we are smrt. 🤣

@Neymarinet 3 жыл бұрын

Ok nerd

@supercussion6590 3 ай бұрын

So pretentious. So unattractive.

@victor9 3 жыл бұрын

I bought a humidifier this winter and OMG I don't understand how insanely good it is. no dry mouth no itchy skin no chapped lips or dry skin. get one you will love it!

@NoHandleToSpeakOf 3 жыл бұрын

I second that. Single most valuable purchase I made. Keeps COVID away by maintaining body's defenses in good shape

@pavel9652 6 ай бұрын

Depends where you live. I have dehumidifier running most of the year except summer.

@parnoidrednik7588 2 жыл бұрын

Thank you for this

@bhartley1024 3 жыл бұрын

Well, since this video was disappointing, I will share something I only wrapped my brain around recently. Relative humidity is the ratio between the current partial pressure of gaseous water and the vapour pressure of water at that temperature. It really has nothing to do with the air, other than its temperature, and the air doesn’t really “hold” water. Partial pressure is like this: If I have a gas mixture of 80% nitrogen and 20% oxygen, and the pressure of that gas is 1 bar, then partial pressure of the nitrogen is 0.8 bar, and the partial pressure of the oxygen is 0.2 bar. Vapour pressure is like this: I take a gas bottle and pump everything out of it so it is a complete vacuum, then I add some water to it. Some of the water will stay as a liquid, and some will turn into a gas. The pressure of the gas at a given temperature is the vapour pressure. If I heat up the gas bottle, the liquid water will boil, the vapour pressure will increase and there will be more water as gas and less water as liquid. (this is how heat pipes work btw) The vapour pressure of water is pretty low, 23.388 millibar at 20C. If the partial pressure of the water vapour in 20C air was 23.388 mbar, the humidity would be 100%. If the partial pressure of the water vapour in 20C air was 11.694 mbar, the humidity would be 50%. As usual, if I’m wrong, the internet will correct me shortly.

@route2070 3 жыл бұрын

Now im curious if scishow has a heat index vs. wind-chill vs "feels like temp" video.

@connecticutaggie 3 жыл бұрын

One of the other useful things about dewpoint is that it often tells you how low the temperature is going to get at night. This is because as the temperature drops, each degree of temperature drop takes about the same amount of energy loss. This all all changes though when you hit the dew point and to get lower, the dew point has be lowered by condensing water out of the air. This takes a lot more energy. This is pretty clear if you look at the daily temperature graph in a humid area. The graph looks really flat at the bottom where the temperature hits the dew point.

@umi3017 3 жыл бұрын

I normally check weather with local airport's METAR, and there is dewpoints....

@vcxlll 3 жыл бұрын

Thank you for explaining relative humidity, from an island on the equator that is oppressibely hot and humid all year round.

@TamjidShafiq 28 күн бұрын

Really helpful!

@kc9scott 3 жыл бұрын

I learned about dewpoints years ago when I took pilot training. Today, at home when I need to decide whether to open the window for cooling, or use the air conditioner, I check the weather report and see if the dewpoint will be below or above 55ºF (as well as the outside temperature being appropriate). If the dewpoint is below 55ºF, I know that when that outside air comes in and warms up to room temperature, it will be a comfortable humidity level.

@HastyChester 3 жыл бұрын

% RH is something that I have understood for so long that I don't ever remember not understanding it. But I am probably getting old, and measuring environmental conditions is part of my occupation. Learning that the measurement confuses people that don't need it in everyday life is like when I had the epiphany that a friend didn't understand how variables were used in algebra. I was trying to help them with their homework, and they kept nodding, but didn't actually seem to get it when completing assignments. Once I understood that "letters in an equation" didn't make any sense to them, I was able to properly teach! Always ask questions! We all have different life experiences and are operating from our own, accumulated data sets. Sometimes, things that seem simple and universally understood to one person are alien to another, but we all are capable of understanding if we have the time and the want to.

@McCallEdwards 3 жыл бұрын

This is giving me terrible flashbacks to psychrometrics in my HVAC course in college

@KM683250 3 жыл бұрын

I learned this in seventh grade. Thank you, Miss Furlow!

@Kamel419 3 жыл бұрын

me, someone who spends way too much time learning useless stuff: oh, it is exactly what i thought it was :(

@Meowvela 3 жыл бұрын

I had a similar reaction. ^///^;

@DaimyoD0 3 жыл бұрын

I agree with the sentiment, but I actually think this is pretty useful information!

@l.zevicreations 3 жыл бұрын

I know right!? AAAAAAAAAAAAAAAAAAAAAAAAAAAA

@Meowvela 3 жыл бұрын

@@DaimyoD0 Does make sense! Just was a little disappointing to realize I already knew a lot about the topic. Did learn what the "dew point" is called though! So I did still get to learn something. I knew the concept, but not the name.

@OneTrueCat 3 жыл бұрын

Same. Just enjoy knowing that you're a well learned individual.

@kevinrdunnphs 3 жыл бұрын

Air doesn't really "hold" humidity if there were no air the water would still try to evaporate till there's an atmosphere of water vapor at the vapor pressure for that temperature. And relative humidity is the percentage of vapor pressure that the current partial pressure of water vapor is.

@patolorde 2 жыл бұрын

This comment is very important

@trigtrigger9794 6 ай бұрын

Like the video and information 😊

@bxlawless100 3 жыл бұрын

Great great video!!! My house is so dry in the winter even if I raise the humidity so high!!!

@EOTBuk 3 жыл бұрын

Was only this weekend wondering about this. Temp/RH monitor in green house rigged up recently. Temp goes down over night and HR goes up and vice versa in day. Makes sense now!

@harmonicaveronica 3 жыл бұрын

Well that explains why I've felt terrible all day! My sinuses like to throw a fit when it's dry but it's hard to tell if it's pure allergies or allergies that have been exacerbated or pure dryness. Turns out it's very dry today! We're at the point in the year where relative humidity isn't particularly intuitive because it's still pretty chilly, but the dew point is only 23F

@jorgeemilioreyes 3 жыл бұрын

You should do one of these for the Sun Protection Factor (SPF), the one in sunscreens. It's commonly confused with a percentage (%) of protection against sun radiation. But it actually isn't

@cernejr 3 жыл бұрын

I use Dew Point - it gives me very clear idea how humid the air will feel.

@christelheadington1136 3 жыл бұрын

When you walk out the door, into a wall of air....

@DASPRiD 3 жыл бұрын

I can confidently say: Relative humidity is exactly what I thought it is ;)

@LibertateMuzicala 3 жыл бұрын

Good one

@dianewallace6064 3 жыл бұрын

I love Michael's voice.

@greamespens1460 3 жыл бұрын

Great video.

@whateverrandomnumber 3 жыл бұрын

I always thought relative humidity implicated how much the air absorbs water molecules from surfaces (like you know, your skin). High relative humidity (i.e. inside a cloud) already feels kinda wet, so it wouldn't absorb any more moisture from you. The opposite from a dry air. But indeed the "feeling" of relative humidity kinda feels logarithmic with temperature. Or exponential, depending on how you frame it (by "feeling of dryness" or "feeling of moistness").

@hulkgqnissanpatrol6121 3 жыл бұрын

Very interesting looking at my hot house data logs in the afternoon's. One temperature I never want to feel again is 70c and 100%Rh. The feels like temperature is over 155c!

@hulkgqnissanpatrol6121 3 жыл бұрын

@Chance Plays 😂 it was in my old hot house when the exhaust fan didn't engage.

@patrickfitzgerald2861 3 жыл бұрын

Just for fun I paused the video and checked the dewpoint here in Tucson, AZ. It was hilariously low at 21°F (-8°C), with an air temperature of 81°F (27°C) . . . ah, life in the desert! 😎

@carlosmp2043 3 жыл бұрын

I have thought about this forever, and the quick answers never satisfied me

@supercurioTube 3 жыл бұрын

Good explanation! I'm now looking for a good weather app that supports dew point graphs and predictions 🙂

@AaronOfMpls 3 жыл бұрын

I'm in the US and use NWS NOW myself (unofficial, for Android, at nwsnow.net [where I've got it since it left the Play Store] or Amazon app store [which I don't have]), or just the NWS website (www.weather.gov). Not sure what's best in other parts of the world.

@greedtheron8362 3 жыл бұрын

Man, I really wish you put this video out two weeks ago, because I just bought a little thermometer/relative humidity device and I was wondering what exactly those numbers mean. Now I know they mean nothing usable

@sheepledtotheslaughter4917 2 жыл бұрын

Finally a video that broke it down for me to understand it.

@Primalxbeast 3 жыл бұрын

If the relative humidity is in the 90s at night, that still means that the sweat on my skin can't evaporate because there's already so much water in the air. The total amount of actual water in the air may not be any more than in the day, but if the air can't hold as much water at night, the sweat has nowhere to go. I live in Florida without AC, and the humidity gets unbearable at night.

@tomlxyz 3 жыл бұрын

Why are you sweating if it's not warm?

@Primalxbeast 3 жыл бұрын

@@tomlxyz The temperature doesn't drop much at night in humid climates.

@thatgirl6155 3 жыл бұрын

The dew point is 76F right now and the temp 78F. I love that air conditioning exists.

@victoriabarclay3556 3 жыл бұрын

Just today I was thinking “ relative to what?” And you gave me my answer. Living in Houston, we know how humidity feels.

@D-Vinko 3 жыл бұрын

The temperature, for anyone else asking.

@mattbrown4895 3 жыл бұрын

Maybe you can do a more in-depth article that touches on grains of water, the absolute quantity of water in the air at a given temperature. I found that a fascinating part of my greenhouse management class for horticulture. I have a sling psychrometer and it's fun to check the rH with my kids.

@duckgoesquack4514 3 жыл бұрын

Trying to find a video about the first hygrometer, but nothing showed up...

@D-Vinko 3 жыл бұрын

That's because that technically isn't the first one, that's the first more-accurate one. en.wikipedia.org/wiki/Hygrometer#Hair_tension_hygrometers

@michaeljames5936 3 жыл бұрын

I think you forgot an important part of your explanation. The Dewpoint is the temperature at which air, with as much moisture in it, as there is in the air right now, would condense into dew. If the air today has very little moisture in it, it would have to get pretty cold, before it would be so saturated that it would condense. If the air has lots of moisture, it has enough to condense at a much higher temp.

@pate_98 3 жыл бұрын

Can't really understand why dew point should represent humidity better. If we take a closed enviroment and raise the temperature the air will feel drier, the dew point stayed the same only relative umidity changed (preassure should not change). This example can be observed during winter if you turn on the heater and you do not have a humidifier. Sorry for the bad english

@GayAllTheWay2024 Жыл бұрын

It just became fall. Early in the morning it was very humid and I felt cold. I put a blanket on and woke up very sweaty. So I guess sometimes humidity can feel hot and miserable and other times it can feel cold?

@Alenajellybeans 3 жыл бұрын

I use dew point to know if I should use a humectant or an emollient in my hair

@thephotoyak 3 жыл бұрын

Do hygrometers measure realative humidity accurately at all temperatures. Or just at room temp? I always figured cheap ones measured total water in the air and were only accurate at room temp, but I don't know for sure.

@davidbass6780 3 жыл бұрын

I got a question related to calculating dew point. I found a dew point calculator online that uses humidity and air temp to calculate dew point. Is that an accurate way of calculating dew point?

@edwardblair4096 7 ай бұрын

Whether it is a good or accurate way to calculate dew point depends on the quality of the formula that the calculator uses (plus the accuracy of the measurements you are using as inputs). There are well established formulas for calculating dew point from air temperature and relative humidity. Assuming the online calculator is from a reputable source, it should be accurate.

@antoniong4380 3 жыл бұрын

So the dewpoint temperature can't be calculated or something? (saying that it is a constant 1atm outside)

@hanquanphoon5664 3 жыл бұрын

I thought relative humidity is important not for the "feeling of stickiness" but for how much it adds to the feeling of heat, because relative humidity affects the rate of evaporation of sweat off your body more than absolute humidity.

@michaelesposito2629 3 жыл бұрын

Just watched a 5 year old video of him, and then straight to this one. Wow. What a change

@ThisOldSkater 3 жыл бұрын

Covid "19". I think a lot of us can relate.

@MrMctastics 3 жыл бұрын

@@ThisOldSkater Over the course of this pandemic I’ve gained 30 pounds and then lost 30 pounds. Currently, I’m in a “I eat food to survive” phase

@hurlaky43 3 жыл бұрын

This is also how dehumidifiers & Air Conditioners work: by cooling the air below the dew point, a lot of the water vapor condenses & they blow out drier (& cooler) air.

@pavel9652 6 ай бұрын

This is his compressor dehumidifiers work. They do heat up air little bit, sometimes, as compressor has to get rid of heat.

@dscrive 3 жыл бұрын

A few weeks ago I put a thermostat/hydrometer in front of the vent on my window AC, I assumed the air would be bone dry and cold, it was cold, but showed a humidity level of 80-99%%, I checked another meter further in the room, and it showed about 60% humidity. That was when I, unintentionally, finally grasped the concept of "how much water the air can hold at that temperature" I was messing about because I bought about a dozen of the meters for cheap off Amazon because I wanted to see if I actually needed a dehumidifier in my room/house (Mississippi), I do :/

@robfilmer 3 жыл бұрын

Cool vid !

@banditkade 3 жыл бұрын

Ha! You guys posted a similar video I think maybe 5 years ago; I've used dew point to determine humidity ever since!

@valerierodger7700 3 жыл бұрын

I already understood what relative humidity meant, what I don't understand is the reference to weather channels and apps not having the dew point. My go-to has always been Environment Canada weather, and they've always had the dew point listed.

@fairybeliever5599 3 жыл бұрын

Finally! I get the answer to why my weather app kept showing soo high humidity during winter.

@josephteller9715 3 жыл бұрын

Of course it might have been useful to note the point of difference between Temp and Dew Point where the humidity has its most obvious effects, as in when it will 1) Fog Eye Glasses 2) Fog The Air 3) Produce Drizzle

@peterjohansson4570 3 жыл бұрын

"Water must go from a gas to a liquid"? Does not sublimination work both ways? (You can dry your cloths in sub-zero C° degrees, due to waters ability to subliminate).

@documenter4907 3 жыл бұрын

10C dew point is comfortable for most people at what external temperature?

@LuisAldamiz 3 жыл бұрын

Great, I've been seeing hygrometers (spelling?) since I was a kid and could never figure out what they meant, it was all the time the same value anyhow: "high", so I was also perplex why would they care about it when it never seemed to vary (at least not much).

@mattwhaley1865 3 жыл бұрын

Former floridian, the relative humidity has always been high and always made you feel drenched in sweat after five minutes of being outdoors. Compare that to living 5000 miles+ upwards in Colorado, 5 minutes with the same relative humidity, i don't feel hot and sticky.

@flyonthewall2450 3 жыл бұрын

I stay in a subtropical area where the dew point often gets 22-23 degrees in summer. It's hell

@angelapotter8084 3 жыл бұрын

I need covid to end so that I can get some more scishow quiz show episodes.

@sutil5078 3 жыл бұрын

the video says if the dew point is 15c (59f) and that if the real temperature outside is closer to that dew points of 15c it will be unpleasant. 15 degree is very very pleasant temperature, even if there is high level of humidity... here in the desert where I live , in winter when it is winter and rain .. temp maybe 15 , humidity maybe relative humidity is 60% ... but I never checked the dew points but even if it were closer to real temperature of 15 it is hard to imagine it is uncomfortable. Am I missing something, or desert climate is an exception?

@TheRealWormbo 3 жыл бұрын

I think that explanation is slightly off. The thing about the dew point temperature is that it's describes the absolute humidity in a particular way. As a result, within a reasonably large margin, the dew point temperature itself can be taken as an approximation of how "aweful" the humidity situation may feel. If it hits 18-20°C (roughly 65-70°F, according to Google), you know it's going to be quite unpleasant regardless whether the actual temperature is closer to 20°C or over 30°C. On the other hand, if the dew point is 10°C or lower and it's hot, you can sweat very "efficiently", so the temperature is a lot more bearable.

@sutil5078 3 жыл бұрын

@@TheRealWormbo thanks for your kind response, I understand it as you explained, and in fact they say Dew points is the temperature that is required for the moisture to reach saturation.. that is another way of looking at it.. d. p. of 10 they say is pleasant above 15 it becomes more and more unpleasant fine.. but I may have explained my self wrong, I meant if the real temp. is 15 it would be very pleasant regardless of humidty.. dont you think.. I lived long time ago in Daytona and in dec. was so pleasant even if it were 60% humidity level etc.. here where I live now is 44 c right now.. 110 .. all summer.. but when winter comes 15 , 10c or even 7c.. when it is 15 and the humidity were to be 70 or 80 it would be hard to believe that 15c which is exactly 59f would be unpleasant regardless of the dew point. It may work when temp at 27c , 30c.. appprox 85f or 95f then yes. maybe their is a range of real temperature where d.point would be irrelevant.

@jakobrosenqvist4691 3 жыл бұрын

It's also worth noting that the relative humidity will be extremly low indoors when the temperature outside is low. If it's - 15°C outside with a humidity of 90% and you take that air inside and warm it up ro 20°C that humidity will drop like a stone contributing to the dryness of the indoor air in winter, and the colder it is outside the more pronounced the effect is.

@jakobrosenqvist4691 3 жыл бұрын

Also, reltive humidity works exactly the way i thought.

@ToMPaSHKoV 3 жыл бұрын

You mean it's not when your uncle sweats all over you at Thanksgiving dinner?

@timcarder2170 3 жыл бұрын

I watch the weather network on tv, more than I look at my phones weather app... I even downloaded the weather network app, but still watch the channel more.

@youmaycallmeken 3 жыл бұрын

How about the percent of the air that is H2O (by volume). Would that be so hard to measure? Wouldn't that tell you how wet the air feels?

@MegaBrokenstar 3 жыл бұрын

Another common misconception is that when the relative humidity gets >=100%, it will start raining. Not necessarily. The default when the relative humidity reaches 100% is the formation of clouds, ie fog when it happens at ground level. More than just that has to happen for rain to form.

@alexlehto2525 2 жыл бұрын

why is this more helpful than my college level meteorology class

@masterchaoss 3 жыл бұрын

I live in southern California what's humidity?

@SaschaBurkhardt 3 жыл бұрын

great!

@wmarclocher 3 жыл бұрын

I've heard if the humidity is over 50% you can ball park the dew point by subtracting the humidity (as a whole number) from 100 and divide that result by 5, that will give you the degrees, in Celsius to subtract from the temperature to get the dew point. (75 F and 60% relative humidity = 60.6 F ( 100 - 60 = 40, 40 / 5 = 8, 8 * 1.8 = 14.4, 75 - 14.4 = 60.6 (actual dew point would be about 62F)