Do not live near bodies of water. Also in the US south where we’ve had excessive heat warnings. I suppose the sun plays into it, but help me understand please. Thank you
In: Other
Humidity is a measure of how much water is in the air relative to how much it can hold. Warm air can hold more water than cooler air, so as the air cools the capacity decreases even if the total amount of water in the air stays the same. Think of it like pouring water out of a big bucket into a smaller one – what might take up 50% of the big bucket would take up 100% of a bucket half its size.
When you heat a gas it expands. When it expands there’s more space between the atoms and molecules so more can fit inside. For instance, water.
When the temperature drops, that extra water can stay there (up to certain amount) so now the gas wants to be smaller and there’s “more” water per cubic space. It’s called relative humidity: average humidity in relation to air.
Extra:
The more water you have in the air, if it’s hot, your skin doesn’t get dry. You feel hotter (water can’t leave your body taking away heat).
The more water you have in the air, if it’s cold, the faster that water steals your heat, so you feel colder (water takes a lot of energy to change temperature, more than air).
Then there’s wind chill, the faster air moves, the cooler it feels. So you get the “feels like” temp which is completely subjective and personal.
It doesn’t necessarily. As the temperature drops at the end of the day, absent some mechanism to remove moisture from
the air (e.g. precipitation, weather patterns, etc.), the absolute humidity and dew point can stay constant. The relative humidity will go up because that’s a measure of how much moisture air can hold and warmer air can hold more moisture. So it goes from low relative humidity to high relative humidity as the air temp drops at the end of the day, but the amount of moisture in the air stays about constant.
If you take one cubic meter of air from somewhere on earth, it’ll have a bunch of different gasses in it. Nitrogen mostly, then oxygen and some amount of water.
The water will be in vapor form, completely invisible, if you pick that cubic meter from a dry place, and it will be in vapor and liquid form if you pick it from inside a cloud or a foggy place. The liquid part will be in tiny droplets in suspension that will make is look more opaque / foggy.
If your cubic meter is foggy, you can make it clear again by heating it up. It’ll cause the droplets to evaporate into vapor and become invisible.
If your cubic meter is clear, you can make it foggy by cooling it down. Some of the vapor will condense into tiny droplets and fog up the space.
When temperature drops at the end of the day, some of the vapor in the air can turn to droplets and deposit as dew on the ground. If the air is quite dry, it might not reach that point, but it will get closer to that point, making evaporation of already liquid water slower. So clothes will dry slowly. Your sweat as well, which translates to us to “feeling humid”.
It doesn’t. Relative humidity does however.
Colder air can hold less amount of water.
Therefor, lowering the temperature while maintaining the same amount of water means the air is more ”saturated’ with water. (= Higher relative humidity)
Latest Answers