Brief Notes on Cold Season (Winter) in India
The Cold Season:
i. The cold weather season begins from mid-November in Northern India and stays till February.
ii. December and January are the coldest months.
iii. Temperature decreases from south to north.
iv. Average temperature of Chennai, on the eastern coast is between 24°-25° Celsius. On the other hand in the northern plains, it ranges between 10°-15° Celsius.
v. Days are warm and nights are cold.
vi. Frost is common in the north.
vii. Higher slopes of the Himalayas experience snowfall.
viii. North-east trade winds prevail over the country.
a. They blow from land to sea and hence, for most part of the country, they are a dry.
b. Some amount of rainfall occurs on Tamil Nadu coast from these winds as they reach here after blowing over long distances on the sea and absorbing moisture.
ix. In the northern part of the country, a feeble high-pressure region develops, with light winds moving outwards from the land.
x. Influenced by the relief, these winds blow through the Ganga valley from west and north-west.
a. Weather is normally fine.
b. It has clear sky, low temperatures and low humidity and feeble variable winds.
xi. A most notable feature of the cold weather season over Northern Plains is the inflow of depressions from west and north-west.
a. They are low-pressure systems called the Western Disturbances.
b. They originate over the Mediterranean Sea and Western Asia and move into India, along with the westerly flow.
c. They cause much-needed winter rains over the plains and snowfall in the mountains.
d. The total amount of winter rainfall ‘Mahawat’ is small.
e. They are of immense importance for the cultivation of ‘rabi’ crops in North India.
xii. The Peninsular India does not have a well-defined cold season.
xiii. There is hardly any noticeable seasonal change in temperature pattern due to the influence of the sea.