Why Does Humidity Make It Feel Hotter? 

I hate humidity. Feels like you're walking around in someone's breath

"If the dew point is above 18C then it's going to start feeling sticky and gross." I checked the dew point for me in Florida and it's currently 23C. So yeah.

Humidity is the worst! It takes uncomfortable temperatures and makes them unbearable. I live in Korea and the winters are hella dry and the summers are way too humid. Translation: in the winter I'm constantly suffering from broken capillaries in my nose and dry skin even though I have the humidifier going AND in the summer I'm a hot, sweaty, disgusting mess.

Well, the wind also matters a lot. Seriously important to mention as well.

As a meteorologist, I wanted to say that this topic was handled extremely well! Much better than most explanations. Thank you, SciShow! ^_^

In Canada, many weather reports include a "Humidex" value, which uses the dew point to calculate how hot it "feels." I find it really reliable. For example, it might be 28 degrees Celsius, but the Humidex might be 33 degrees...given the high humidity, it feels like 33. And "Humidex" is an awesome word too.

So... Don't you have "felt temperature" in forecasts in the USA? In Germany they always say something like "18 degrees, feels like 21 degrees", taking humidity, windchill and intensity of sunshine into consideration. Makes it pretty easy to know what to expect.

I used to worry about hot and humid weather. Now, I just don't sweat it.

I'm old enough to remember Farenheit in England but, for the past 30+ years, we've used Celsius, and I've become more familiar with that. It's great to see a simple explanation about humidity, plus explained in the 'international' standard of Celsius.

It feels hotter because *The Sun is a Deadly Lazer*

I love Hank, he's become one of the best presenters on youtube and is constantly a joy to watch

Thank you for using the metric system. -The rest of planet Earth

In Louisiana, when the relative humidity matches the temperature (for example, 90 degrees Fahrenheit) it’s bad. Also, we have something called the Heat Index, the equivalent of the Wind Chill Factor. So we can have a forecast of 90 degrees with a Heat Index of 105. That’s when it’s really bad

This has been incredibly helpful for me here in central PA where it feels like we're swimming in the ocean. This has been the most 'humid' summer I can remember. It is insane. I'm glad to have an accurate tool in my arsenal to help gauge the outside temperature better. Thanks Hank!

Can confirm humidity makes a MASSIVE difference. Summers in the midwest were absolutely unbearable even when it was 70 (which was rare, it was usually 90 - 105). 75F in humid Missouri genuinely felt like 90F in dry-summer Montana. Case in point, it's actually a little humid today here in Montana (60% humidity), and the 80F feels around 85F instead. But a few days ago it was 90F with only 15-20% humidity and that actually felt like 80, maybe even 1-2 degrees cooler.

I love how you guys use Celsius... Thank you!!!

Dear God, thank you for hearing my prayers about the Celcius scale. This video made my life complete.

35c with 50% humidity... Child's play!! I was in New Orleans last summer and the air was so humid you could wear it, and it was hot. It was so hot and humid that my glasses fogged up just looking out of the window. So hot that I saw a dog chasing a cat and both of them were walking

Here in Minnesota the summers often have a dew point of 60 or higher. Funny to hear 23 as feeling muggy.

Foothills in nc. 93 plus degrees, no wind and 70 and above percent humidity...I work outside. I get heat exhaustion every day. Head feels like it will expload, dizzy, soaking wet, heat rashes. It doesn't matter how much water and sports drink you drink. It is depressing and a miserable existence. Not to mention the mold, mosquitoes, and the exterior of houses warping from it as well. It hits us around mid March and doesn't let up until October. Don't move here if you want to work outside. Better yet, stay away from here. It will make you depressed. Its oppressive and feels like death.

Wait... Did I miss something? Why no mention that the increase of moisture in the air holds and transfers more energy faster than dry air?? It's the same reason why a dry sauna can be much hotter than a steam room but not feel as bad, why you can be outside in 120F in the desert but in a hot tub of the same temp you'll likely die, and why holding a piece of cold plastic will feel warmer than a piece of metal of the same temperature.

The dew point here in NC right now is 78° 80% Humidity. 88°F Sunny and feels like a sauna.

I don't like humid heat because your deodorant starts melting off, everyone is sticky, you can only wear cotton clothes and they'll still feel damp five minutes out the door!, your hair does the most, you always feel like you're suffocating, ugh just no!

as somebody who lives in one the driest states in the us, humidity is overhated. i hate dry air. sure hot humidity is unpleasant but high humidity with mild temperatures (like san diego in the late summer)? perfection.

I live in a hot climate and I’m always fooled when the forecast shows 28°C(82°F) but it feels like 33°C(91°F)instead.... I was always so excited to see the forecast showing a cool 24°C(75°F) but INSTEAD it feels way warmer than that... reality is often disappointing I Guess.

I live in Abbotsford, British Columbia. I was recently in Nevada, Texas, Utah, New Mexico...and Arizona. While those were hot, it is about as hot here right now and much more humid. I always prefer when it gets cooler.

I really like the phrasing "When you need to cool down, your blood vessels open up, letting blood flow to your arms and legs" implying that when it's cool outside, there's actually no blood in your limbs

Makes me feel so smart when I guess the answer correctly before the video, usually I am way off base but I managed to nail this one. Maybe I heard it before and forgot but I'm gonna stick to thinking I figured it out on my own.

What about during cold? I am certain that the Atlantic chill in humid, 0C winter cold in Ireland feels more severe than a biting frost at -10 in say main land Europe,

I lived in singapore. When i went to a even warmer country but with much lower humidity, it was like a chill weather for me

According to Wikipedia, the body is not 37 C or 98.6 degrees F, but in fact changes depending on all sorts of factors like the time of day and where you are in your menstrual cycle and what time of the year it is, and where the temperature is taken is yet another thing that changes the outcome. Internal temperature is higher than 98.6 degrees, as well- it isn't just that the heat is isolated from the thermometer, it's also that the number is just wrong. Where does the claim of this being the body's temperature even come from?

That would explain why it's nice in Georgia right now (as of August 1, 2017). The dew point is at 19° today.

This video helped me understand "Dew Point" so thank you very much for this video Hank. 😍😘

I, as a Floridian, am well aware of public enemy #1: humidity

And that's why my country which has an average temperature of 32 deg, feels much hotter than most countries which summers can reach 40 deg. Because my country has an average dew point of 25 deg (70% relative humidity @ 32 deg)

Hmmmmm... I will do a thing now I rarely do. And it's to post to SciShow that they missed out on a BIG part of the explanation. Which also made them make a mistake in the title. Humidity does NOT ALWAYS make it feel hotter. Anyone living in a cold country like Canada or Norway will know this. When it's cold, And we're talking

Speaking as someone who lives in southern Mississippi these are words to live by there's a dew point of 22.7C outside right now.

Thank you for the explanation and specially for using celsius

I just saw this for the first time and so I went and checked my dew point. Well if 18 feels muggy, my 24 most feel great. Love Florida weather

The dewpoint is high in both Phoenix and Las Vegas.

I live in California and when it is 110F it is bearable, however, when I went to tokyo and it was only around 85F-90F it felt like literal hell due to the humidity, lack of air conditioning, ton of walking, crowds of people, etc.

Life in Florida... I call it swamp weather. I can't stand it. What's the point of spending an hour on my hair and make up when I melt as soon as I step outside? I ask myself that, everyday.

Humidity just makes doing anything outside 10x more miserable

"If the dew point is above 18 degrees Celsius, it's going to start to feel sticky and gross." AKA 95% of the year in Florida.

Dew point is 76% right now just out side NYC at 1am!!!! 74 degrees out but is sweltering and we’re going into a 90 degree day and the humidity is 91% right now after the 4th of July in 2024! The summers are getting hotter and wetter! One year the grass died and last year it was hot and a lot of peoples basements flooded because of the heavy rains that saturated the ground and this year, summer basically started in spring and it’s only getting more and more humid. In the 1990s, 90 degree days north of nyc were rare so when they did happen, it was a big deal. Now we’re gettin 90 degree days for a week with brakes of 82 plus. It’s just freaking hot! It’s reminding me of south beach in the summer in the 90s. I can’t imagine decades later with the heat rising this much this far north what Miami is like. Vegas I’m Aug I felt for the fist time before vivid hit and it was 110 but dry heat. You barely sweat. It’s so different but more tolerable surprisingly than 90 degrees after a thunderstorm! What is happening to the weather this year! We’re not even in august yet and we have had a months worth of 90 degree days.

This whole Celsius/Fahrenheit thing is making me crazy! Please give equivalents no matter what system you are using. Thank you.

Times like these I'm glad I live West of the Rockies. No humidity problems here!

I only realised near the end of the vid they actually used Celsius! Thank god, I didn't have to Google 'Murica-Temp :P

Humidity doesn’t make it feel hotter. We just sweat. I’ve been in the dry heat of the Midwest and it was terrible. I was thirsty all day, had a dry throat all day. I’d sweat and it would be dry in a minute. It got over 100 degrees outside and the part of the bed by the window felt like hot lava. Then got back home to Miami and thanked goodness it rarely goes over 96 degrees and we have humidity in the air. Generally 83-89 degree weather perfect for playing sports. Plenty 73 degree days to just sit outside. Lots of rain. I’ll take humidity over dry heat any day. Wanna know how a fish feels outta water? Leave south Florida and visit the Midwest for the summer. If you make it back write a book

Miami always has like 500% humidity 😧

It is currently 98% humidity outside with a temperature of 27C. This is criminal to have to work in

Dew point, got it. Thanks!

I live in Mumbai and you have no idea how badly I needed to know this!! Tysm

I live in Louisiana. Soo, I literally don't know what "no humidity " feels like.

I live in Miami and it can be 80 degrees minimum in the summer but since there is soooooo much humidity it makes it feel like 110 degrees

I'm in the Washington DC area and it gets so humid that clothes feel heavy on your back

I finally feel smart! I learned all this in water damafe restoration school. To my surprise I discovered first hand that 90 degrees can feel like 73 degrees when dehumidifiers and fans are introduced with the ac set on 90

2:10 "The higher the doo point, the grosser you'll feel..." Of course.

The Humidex which, I just learned is a Canada thing, uses dew point to calculate humidity comfort. I’ve generally found it accurately conveys the level of comfort or dis to expect.

Answer: because science

As a college kid who took a meteorology class, Relative and Absolute humidities are a bitch! I'll take dry heat any day of the week thank you.

In Arizona, everything makes it feel hot!

I live in South Florida. Humidity is crazy down here!!!

I thought it said humanity when I read it, I'm an idiot.

It's April 30th, 2024 at 6.15 AM and the temperature in Bangkok, Thailand is 30c but it feels like 36c or even more as the humidity is 86% & the dew point is 27c. 🔥

I should point out that this works both ways. With lower temps feeling a lot colder too as humidity increases. I think close to 30 degrees humidity makes the least difference and the further you go the colder or hotter it feels.

My city is in a valley that boarders the Ohio river. That is bad combination. All the water that evaporates off the river just kind of hangs around. There isn't the air circulation that normal river-bordering cities have, and thus the valley just traps all that moisture. The humidity rating will regularly be 100%. If we get a day with the humidity _only_ at 80%, it feels downright cool in comparison. I've heard of regions that are hot, but it gets described as a "dry heat", to me that is such an abstract concept, that I can't even begin to imagine what it would feel like.

Some people will walk out of an air conditioned building out into the blistering hot and humid air and say "It's a beautiful day". I don't understand how someone can be so optimistic, when the "heat index" is over 100*F (such as 112*F heat index). To me, a beautiful day, is when you can be outside and feel like you are in a cozy climate controlled zone, like 60*f - 73*f with clouds to protect you from sunburns and proper humidity so you don't dehydrate and don't sweat. I don't like when the weather, makes being outside for several hours (especially if working), a miserable experience. I hope we have a long cloudy cold winter this year. I LOVE hearing people complain about it being "too hot outside" because growing up as a kid, all I heard was people talking about how wonderful the hottest time of the year is and how horrible winter is. It's like I watched commercials and everyone is excited and happy because It's the most physically painful time of the year, so let's all go outside and celebrate. When the weather is mild, we might as well stay inside and be sad. Logical? Well, it isn't logical to me. I highly doubt these people who love the heat so much, turn their heater on year-round, to get their house between 100*f and 120*f, and yet they act like it's a good thing...

If you've ever lived here in Missouri, you'll know the humidity here is brutal especially because of how dry it can get. That and the weather is bipolar as hell all year round

30 Celsius = 85 Fahrenheit. Your Welcome!

Google analytics must show that the majority of views must be outside the USA. I'm from the land down under. (Australia). I love how you use the metric system.

Again, thank you so much for using metric units. Fun fact: there are almost the same number of non-American English speakers in the world than American english speakers. And they all use the metric system.

I was in Kuwait and temperatures over 120 degrees were not uncommon during the summer with the relative humidity being on average over 90%.

It's not the Humidity. it's the Dew point. In the Middle of the Winter. the Humidity can be in the 70's-80's. Dew point is what We Feel.

Great video, thank you.

*So the point is try to avoid the Dew!* *Mountain Dew will give you the runs!*

Pretty sure that even though the dew point will get to only 50 F with the air temperature hitting 103 degrees F, it is going to be very hot and sticky here.

Today's humidity forecast: The air is my ocean.

The Humidex value is soooo important to know every day in summer here in Ontario!

On behalf of Canada, thanks for the *Celsius* Scishow! ;)

Having lived 19 years in arizona you never get to cool off the sweat evaporates to quickly to really add any extra cooling vs anytime I was in the south the humidity allowed the sweat to stay and cool me off longer then back home in arizona

Can anyone say south Florida

Louisiana people know this struggle

Hello, SciShow! Do you think you could make a video explaining the current knowledge of cerebral aneurysms? I had one rupture at 19 and after learning so much about them, I would love for a bigger audience to learn of them!

If the dew point is above 98.6°F that means the moisture in the air will condense in your lungs cause they're cooler then the dew point. Your lungs would fill with water and you'd drown in the humidity.

One word: Florida

This is a great video. I have always wondered about this. Great explanation!

Watching this in 90% humidity + no air conditioner. Makes you desperate

That last line really got me thinking. Barns and Noble reminded me of the days I would hang out in Borders after school... hopefully bookstores will always be around.

In Canada, we have humidex. A calculated apparent temperature.

Yeah it feels like I'm sitting on soggy chairs when I sit down😂

Didn't use F, now wearing a winter coat in 90F weather

I was wondering why it was so disgusting that week my air conditioning unit decided it was time to die. (Though why would I cool down after throwing up? I was heating up and heating up, I'd puke, then I'd get really really cold for a minute, then this cycle would restart. I had to go to the hospital and get intravenous fluids, plus an amazing medication that stopped the whole vomiting thing. According to my discharge papers, I had non-intractable vomiting and dehydration. Which doesn't explain why I was freezing after throwing up.)

Extra like for using Celsius!

Hang out at the library and read free books! (Still love you Hank)

It always gets humid when my cousin walks into the room

Think about this: - Summer time: average temp 35 celcius. Peak temp 41 celcius may stay as long as 2 weeks. Average humidity 85%>90%. - Winter time > spring: 8-20 celcius. Humidity 95-99%. Possible rain whole month. You would see water everywhere inside your house, on the floor, on the walls, on the ceiling. Lets think about temp of 8 celcius in that kind of humidity. Welcome to my life.

People who live in Southeast Asia: 😎😎😎

The weather reports here in Canada usually also give a "Humidex" rating which takes into account those details and provides a rough "what it feels like" temperature.

Americans: What's that temp in Fahrenheit? American Scientists: Sorry about them ( yells, get back in the corner, to the Americans)