Air Molecules

• The molecules in the air are too far apart and randomly located to transfer heat from one to another very effectively. Nonetheless, sunlight does warm the air during the day, and solid objects heated from the sunlight can also transfer heat to the air.
  
  

Altitude

• Air temperature drops with altitude because the atmosphere thins out, according to Utah State University. Individual molecules get hotter because they are closer to the sun, but the overall temperature of the air drops because there aren't enough molecules for much heat transfer to occur.
  
  

Angle of the Sun

• Direct sunlight on an area will result in warmer air temperatures. This occurs during the summer months when the Earth tilts toward the Sun. Temperatures drop in the winter, when the Earth tilts away from the Sun and the angle of the Sun becomes less direct.