Climate of West Bengal

A short spring is expected in some parts of the state, especially in the northern parts North Bengal. That is the time when Holi takes place.

Period

The summer season is observed from March to May in most of the parts of Bengal.

Temperature

In most places, summer is extremely hot. The plains of South Bengal feels hot and humid conditions with daily maximum temperature around 35-38 °C.[1][2]Sometimes it nears or crosses 40 °C.[3][4][5][6][7] The western highlands experience a dry summer like northern India. Here day temperature ranges from 38 to 42 °C. Though it can go above or near 45 °C.[8][9][10][11][12] On the other hand, when the Western and Southern Bengal is burning in summer heat, the plains of northern part of North Bengal is generally cooler.[13][14][15] In this area, the daily maximum temperature varies from 26 to 32 °C.[16]It occasionally crosses 35 °C. The summer minimum temperature here remains 18-22 °C. The Darjeeling hill region is the coolest area in summer. Here, the daily highest temperature is 15-25 °C.

Rainfall

In South Bengal, kalbaishakhi storm brings some rainfall due to deep low pressure while the Himalayan region and Terai dooars plains get heavy rainfall during this period.

Average temperature and Rainfall for some cities in summer(March to May)[17]

Period

In the middle of June, the south west monsoon wind enters West Bengal and the monsoon starts.[18]It continues until the end of September.

Temperature

In most places, the temperature graph bends downward as the sky gets cloudy. But the graph of mountains and Terai dooars plains gradually increases until August.

The maximum temperature of South Bengal plains and Western highlands is 32 °C,[19]31 °C in North Bengal plains and around 19-20 °C in mountains. Sometimes, when the sky gets clear, which is known as monsoon break, the temperature rises suddenly. This incident occurs mostly in North Bengal plains and in mountains in July and August, when the temperature soars over 36 °C and 24 °C respectively.[20][21][22][23][24]

Rainfall

Most of the annual average rainfall occurs during this period. Heavy rainfall of above 250 cm is observed in the Darjeeling, Jalpaiguri, Alipurduar and Cooch Behar district.[25][26][27][28][29]Later, blowing westwards, the winds cause average rainfall of 125 cm in the northern plains and western plateau region.

Average temperature and Rainfall for some cities in monsoons(June to September)

Period

Autumn lasts for two months, October and November.

Temperature

In autumn, the south west monsoon wind returns and clears the sky. So, the state gets enough sunshine to be warm in day and releases a lot of heat to be cool at night.

In this time, a maximum temperature of 30-33 °C is felt over the plains and 17-19 °C in mountains. The minimum temperature is normally around 19-22 °C in plains and 6-11 °C in mountains.[30]Sometimes, cold waves blow over the state in autumn.[31][32][33]

Rainfall

In autumn, the south west monsoon wind returns, and north east monsoon wind starts entering West Bengal. Due to their collision in Bay of Bengal, some cyclones are created.[34][35] The cyclones cause some rainfall in the state.

Average temperature and Rainfall for some cities in autumn(October and November)

Period

The winter season usually sets in December and ends in February.[36]

Temperature

In winter, a mild temperature is felt over the plains. The maximum temperature goes 23-26 °C and the minimum temperature remains 9-15 °C in plains of the state. In mountains, winter is severe with the maximum and minimum temperature ranging between 0-12 °C. Higher regions of the Darjeeling Himalayas gets heavy snowfall during winter.[37][38][39]

Though, the night temperatures of western highlands can drop 7-9 °C,[40][41][42]4-7 °C in Siliguri, Jalpaiguri, Coochbehar plains[43][44][45][46]and 10-11 °C in Kolkata,[47][48][49][50] the capital city when cold waves blow. Darjeeling city's temperature drops below freezing point.

Rainfall

Winter is generally dry. Most of the days are sunny. Occasionally slight rainfall occurs under the influence of low depressions in northwest India. These are known as western disturbances.

Average temperature and Rainfall for some cities in Winter(December to February)

The chart below shows the highest recorded temperatures for all months in West Bengal, with place and date.

The chart below shows the lowest recorded temperatures for all months in West Bengal, with place and date.