Let's make some water:
This is one of the weather observation symbols we learned about in earlier lessons.

We said then that the number on the lower left represents the dew point temperature. The number in the upper left represents the temperature. In order for condensation to occur, air temperature must be cooled down to the dew point.

Air can be cooled to the dew point in a several ways.
1. if the air rises the temperature will fall
2. if cooler air moves in and mixes with the warmer humid air
3. at night, the temperature typically falls rapidly without sunlight

Go to the next page to read about the different forms of humidity in the atmosphere.