Answer:Temperature and humidity
Explanation: Air masses are large bodies of air that are characterized by humidity and temperature at any given altitude.
Air masses are humid( moist-containing certain amount of water)when they are formed above the ocean the and are drier when formed on the land.
some air masses are hot because they develop at lower altitude and the air masses formed along the tropics are usually warmer. when two air masses collides it can lead to thunderstorm.