In this process temperature data from meteorological stations were adjusted to equivalent values at sea level with the use of a lapse rate for the change in temperature with elevation. At the same Internet site, monthly mean air temperature maps for the continental United States have been developed from data for the 1961-1990 period. These maps are displayed as a movie to show the seasonal progression in temperature using a color scale to represent degrees Fahrenheit x 10. Composite annual mean temperature from 1950 to 1995. Other Climatic Factors Relative humidity, solar radiation and wind speed are other climate variables, in addition to temperature and precipitation, that determine the water budget of an area through effects on evapotranspiration.
Relative humidity is highest in the coastal regions near the Gulf of Mexico and the Atlantic Ocean.
Sunshine is abundant in the western part of the region and decreases eastward. The percentage of sunshine received depends on cloudiness. Along with the western portions of the region, Florida receives sun about two-thirds of the daylight hours during the year. The sun also shines longer in Florida in the winter than in the northern parts of the country reinforcing the sunshine state identity. Two climatological factors that influences crop growth, but not soils directly, are frost-free days and growing degree days.