Question

As air temperature approaches the dew point, what happens to the relative humidity?

Answer 1

Relative Humidity is a percentage based on how much moisture is in the air versus how much moisture the air can hold. The dewpoint is the temperature that the atmosphere must reach for a parcel of air to become fully saturated. That being said, if the temperature outside is 30 degrees (F or C doesn't matter), and the dewpoint goes from 10 to 20, then the relative humidity has increased, meaning there is more moisture present in the atmosphere.
The easiest way to look at pressure is by looking at the number of air molecules that are in a closed container. Gas molecules expand as they warm, so warming up a container of air means that these molecule will attempt to expand, thus increasing the pressure. Take for instance a soda bottle filled with air, if you heat a soda bottle, then the gases inside will attempt to expand (raising the pressure) and eventually the bottle will explode, but if you stick the same soda bottle in dry ice, the soda bottle will contract, due to decreased pressure. Source(s): Military Meteorologist
Bachelors in Natural Science

Answer 2

As air temperature falls toward the dew point, OR the dew point
rises toward the current air temperature, the relative humidity RISES
toward 100%, my hair dies, and my shirt becomes soaked with sweat.