Discuss with the students that the temperature and water went up. The soil heats faster and it is also darker and holds more heat. Point out that air masses are described in terms of temperature and humidity. Air masses near the North Pole are very cold. Air masses near the equator are very warm.
Air masses are large amounts of air.
They can be hot or cold. Air masses can also be wet or dry. Deserts are hot, dry places. Six air masses push into each other near North America. There are three cold air masses and three warm air masses.