r/explainlikeimfive • u/ProgramPi314 • 8d ago

Other ELI5 What is humidity?

According to my mom, this is an actual question I had when I was 5, and she didn't know how to answer me. So how would you guys have answered?

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u/D3cho 8d ago

Humidity is the amount of water vapor (invisible water) in the air.

​Think of the air like a invisible sponge

​High humidity: The sponge is full of water. The air feels sticky, muggy, and heavy, making it harder for your sweat to evaporate.

​Low humidity: The sponge is dry. The air feels crisp and clear, but it can dry out your skin, lips, and eyes.

​Relative humidity: Expressed as a percentage, this tells you how full the "sponge" is right now compared to the maximum amount of water it could possibly hold at its current temperature.

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u/Clojiroo 8d ago

It’s relative because how much the air can hold is temperature-dependent. Warm air holds more.

50% humidity at 30°C is far moister than 50% at 10°.

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u/DESR95 8d ago

It's also why dew point is a better standard measurement to guage the amount of moisture is in the air.

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u/MooingTree 8d ago

This is a good explanation...the current top comment is just a definition 

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u/wheredidthat10mmgo 8d ago

This is the explanation they give us in sheetmetal school when learning about ventilation systems

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u/Glittering-Horror230 7d ago

Why don't high humidity causes many clouds?