Temperature is an important aspect of climate and can be used to grade climatic zones on a scale of five: (1) Tropical, with annual and monthly averages above 20° C (68° F); (2) Subtropical, with 4 to 11 months above 20° C, and the balance between 10° and 20° C (50° to 68° F); (3) Temperate, with 4 to 12 months at 10° to 20° C; (4) Cold, with 1 to 4 months at 10° to 20° C, and the rest cooler; and (5) Polar, with 12 months below 10° C.

Within each hemisphere, eight basic climatological zones can also be recognized in terms of precipitation: (1) Equatorial: rain in all seasons; (2) Tropical: summer rain with winters dry; (3) Semiarid Tropical: slight summer rain; (4) Arid: dry in all seasons; (5) Dry Mediterranean: slight winter rain; (6) Mediterranean: winter rain, summers dry; (7) Temperate: precipitation in all seasons; (8) Polar: sparse in all seasons.