Climate of West Bengal

Seasons

There are six main seasons in West Bengal: summer (Grishma), monsoons or rainy season (Barsha), autumn (Sharat), late autumn/pre winter (Hemanta), winter (Sheet), spring (Bawshonto) .

Spring

Spring is considered the most pleasant season over the plains of West Bengal and lies from mid-February to mid-March and is also the time where Holi is celebrated. Temperatures range between 20 °C – 30 °C and no rainfall. Though occasional rain or light showers are witnessed due to Western disturbances in North India.

Summer

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

Temperature

In Bengal, summers can be extremely hot and have high humidity. The plains of South Bengal have a daily maximum temperature around 35–38 °C. It can also exceed 40 °C. The western highlands experience a dry summer like northern India. During the day, the temperature ranges from 38 to 42 °C, though it can reach or exceed 45 °C. In summer, the plains of North Bengal are generally cooler than the west and south. In this area, the daily maximum temperature varies from 26 °C to 32 °C. It occasionally crosses 35 °C. The minimum temperature in summer is approximately 18–22 °C. The Darjeeling hill region is the coolest area in summer. Here, the daily highest temperature is 15–25 °C.

Rainfall

Monsoons

Period

In mid-June or early July, the monsoon season starts.

Temperature

In most places, the temperature drops as cloud cover increases. This is less true for the mountains and the Terai Dooars plains, where temperature gradually increases until August.

The maximum temperature of South Bengal's plains and western highlands is 32 °C, 31 °C in North Bengal plains and around 19–20 °C in mountains. Sometimes when the sky gets clear, the temperature rises suddenly. This is known as a monsoon break. This occurs mostly in North Bengal plains and in mountains in July and August when the temperature soars over 36 °C and 24 °C respectively.

Rainfall

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

Autumn

Period

Autumn lasts for two months, October and November.

Temperature

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

At 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. Sometimes, cold waves blow over the state in autumn.

Rainfall

In autumn, the southwest monsoon wind returns, and the northeast monsoon wind enters West Bengal. Due to their collision in Bay of Bengal, some cyclones are created. The cyclones cause some rainfall in the state.

Winter

Period

The winter season usually starts in December and ends in February.

Temperature

In winter, a mild temperature is observed over the plains. The maximum temperature goes to 23–26 °C and the minimum temperature is 9–15 °C in plains of the state. The maximum and minimum temperature in the mountains range from 0–12 °C. Higher regions of the Darjeeling Himalayas get heavy snowfall during winter.

The temperatures of the western highlands at night can drop 7–9 °C, 4–7 °C in Siliguri, Jalpaiguri, Coochbehar plains and 10–11 °C in Kolkata when cold waves blow. Darjeeling's temperature can drop below freezing point.

Rainfall

Winter is generally dry. Most days are sunny. Occasionally, slight rainfall occurs because of conditions in northwest India. These are known as western disturbances.