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and have fall, while the southern hemisphere will start to be toward the sun and have spring.
The revolution of the earth and the angle of the axis produce the sequence of the seasons--
winter, spring, summer, and fall--each year.
5. The Temperature Zones

It is useful to divide the earth's surface into three general types of temperature zones, based
on the angle of the earth's axis and the revolution of the earth around the sun. See figure 4.
a. Tropical Zone. The tropical zone extends approximately 1600 miles (2600 km) north
of the equator and 1600 miles south of the equator. The areas in the tropic zone tend to be
warm or hot throughout the year. See figure 4.
b. Temperate Zones. There are two temperate zones, one in the northern hemisphere
and the other in the southern hemisphere. The northern temperate zone extends north from
the tropical zone approximately 2900 miles (4700 km). The southern temperate zone extends
south from the tropical zone the same distance. Areas in the temperate zones tend to have
warm or hot summers and cool or cold winters. See figure 4.
c. Polar Zones. There are also two polar zones, one in each hemisphere. The northern
polar zone extends approximately 1600 miles from the northern temperate zone to the north
pole. The southern polar zone extends from the southern temperate zone to the south pole.
Areas in the polar zones tend to be cold. See figure 4.