Damp, muggy, sticky, and sometimes unbearable.
What am I describing?
A humid day.
Humidity is when the air has A LOT of water
vapor in it.
Water as a gas is called water vapor.
The temperature outside coincides with how
humid it can be.
Warmer air can hold more water vapor than
colder air.
The muggiest days usually occur during the
peak of summer heat.
When temperatures drop, the air can hold less
vapor and some of that turns into liquid water.
Water that condenses out of the air at a certain
temperature is called the dew point.
Air holding less vapor than it could is below
the dew point.
Think wet grass in the morning!
Absolute humidity is the amount of water vapor
in the air.
The amount of water vapor in the air compared
to the amount of vapor the air could hold
is called relative humidity.
Fog often forms when relative humidity is
at 100%.
