Relative Humidity Isn't What You Think It Is

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

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[f]

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.

[TheZenytram]

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

[Qui-]

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.

[why_though]

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

[tippib]

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

[christelheadington]

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

[DaveSomething]

Relative Humidity is EXACTLY what I thought it was!

[miriamrosemary]

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...

[stevensines]

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.

[collinbarker]

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

[cornbreadfedkirkpatrick]

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

[BronzeDragonWOHS]

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.

[jeff__w]

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.

[SiqueScarface]

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

[HastyChester]

% 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.

[Kerbezena]

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

[pedroff_]

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

[roberthobbs]

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!

[sheldonwheaton]

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

[kennethtaylor]

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.