Indian Geography : Climate of West Bengal April 23, 2017 The Climate of West Bengal The climate of West Bengal experiences hot and wet tropical monsoon climate. The seasonal characteristics of various climate West Bengal is summarized below : Dry Summer climate of West Bengal March to mid June is the hottest season. Day lengthen, heat increases, air pressures falls. The hot air on land rises to make room for the refreshing cool sea-breeze at dusk in South Bengal. Areas far away from the sea are hotter. The dry rocky surface of the western plateau fringe runs hottest around 40°C. After a hot oppressive afternoon, a Norwester of Kalbaishakhi appears, uprooting trees and blowing down huts. But the Norwester, rains and hails bring about cool evenings and are very useful for early paddy (aus) cultivation, summer vegetables and jute. May is cooler than April due to more Norwesters. People from the plains flock to Darjeeling hills where, because of the height summer is as cool around 15° as winter in Kolkata. Wet Summer Monsoon Climate of West Bengal The climates of West Bengal are influenced most by the gigantic wet monsoon air stream coming from the south and south-east. Mid-June to September is a rainy spell. To quench the thirst of dry summer, a gigantic air-stream with rain-bearing low black clouds arrives and bursts with a heavy downpour. Very often they are cyclonic with high wind speeds. The Bay cyclones are the most furious of all cyclones. In Bengal the wet monsoon current comes mainly from the south and south-east. For 3.5 months moderate to heavy rains occur, with sunny breaks and cyclonic bursts. Sometimes it continues for a week. The monsoon giant is very moody and irregular in its arrival and departure. If it in a bad mood, it gives too much water and causes floods or gives too little and causes a drought. If it is in a good mood, it gives just the sufficient amount of water in time Rain is most frequent and heavy on the southern slopes of the Himalayas. The Himalayas acts as barrier to the monsoon current and give birth to mighty rivers. The mean monsoon rainfall in the State is more than 175 cm. The Autumn in West Bengal In October and November the dry monsoon current treats from land to sea. From 22nd September, days shorten and tropical Bengal cools; but over the southern seas, more sunlight makes more heat and pressure falls. The low pressure draws out the cool air under the high pressure over land. The autumn skies are blue with patches of silvery clouds. But for a few cyclonic storms coming from the Bay and dashing the coastal areas. Autumn brings fine weather everywhere. The Winter climate of West Bengal Winter is from December to February in the plains and up to mid-March in Darjeeling Himalayas. The cold is mild over the plains (15°c-18°c) but bitter in nearly freezing points in Darjeeling. The winds are light and variable in the plains but strong in Darjeeling. Sometimes western disturbances coming from the Mediterranean make light drizzles on the plains and sleet and snow on the mountains followed by a chilly cold wave from the north. This cold water, called pachhia, is as terrible as the summer hot wave, called ‘Loo’.