Climatic type, at any place, associated with
a particular time of the year. The change in
seasons is mainly due to the change in
attitude of the Earth's axis in relation to
the Sun, and hence the position of the Sun in
the sky at a particular place. In temperate
latitudes four seasons are recognized:
spring, summer, autumn (fall), and winter.
Tropical regions have two seasons - the wet
and the dry. Monsoon areas around the Indian
Ocean have three seasons: the cold, the hot,
and the rainy. The northern temperate
latitudes have summer when the southern
temperate latitudes have winter, and vice
versa. During winter, the Sun is low in the
sky and has less heating effect because of
the oblique angle of incidence and because
the sunlight has further to travel through
the atmosphere. The differences between the
seasons are more marked inland than near the
coast, where the sea has a moderating effect
on temperatures. In polar regions the change
between summer and winter is abrupt; spring
and autumn are hardly perceivable. In
tropical regions, the belt of rain associated
with the trade winds moves north and south
with the Sun, as do the dry conditions
associated with the belts of high pressure
near the tropics. The monsoon's three seasons
result from the influence of the Indian Ocean
on the surrounding land mass of Asia in that
area.