Weather and climate in Kolkata (West Bengal)

In Kolkata (or Calcutta), the climate is tropical, influenced by the Indian monsoon.
The city is the capital of the state of West Bengal and is located in eastern India, at nearly 23 degrees north latitude.
There is a sunny and pleasantly warm winter from December to February, when, however, the night temperature can sometimes drop below 10 °C (50 °F), so it's better to bring a sweater and a light jacket. Then, there is a very hot period from March to May, before the monsoon, when the temperature can reach or exceed 40 °C (104 °F) in the worst moments, and a rainy season from June to mid-October, characterized by stifling weather, widespread cloudiness and frequent rains. From mid-October to mid-November, before the winter, there is a period lasting one month with good weather and high temperatures, around 30 °C (86 °F).
Here are the average temperatures.

The monsoon season goes roughly from June 5 to October 15, but already in May (and more rarely in April), the first showers in the afternoon can occur. Total annual rainfall is 1,750 millimeters (69 inches). From November to April, the sun shines and it almost never rains.
Here is the average precipitation.

The sun in Calcutta often shines in the dry season, while the sky is often cloudy in the rainy season. Here are the average sunshine hours per day.

From April to December, Calcutta can be affected by cyclones, tropical storms coming from the Bay of Bengal, with a peak of intensity before and after the monsoon, namely from late April to early June and in October-November. The Bengal region is particularly prone to flooding because of the conformation of the territory (we are in the area of the huge Ganges-Brahmaputra delta, and the river of the city, the Hooghly, is a branch of the Ganges).
In recent times, some cyclones that caused major damage in Calcutta were Cyclone Aila, in late May 2009 and Cyclone Amphan, around May 20, 2020. Occasionally, a cyclone can also arrive at the beginning of December, as happened on 11 December 1981 and on 6 December 2021.



South of Calcutta, the sea is warm enough for swimming throughout the year, although it drops to 23/24 °C (73/75 °F) in January and February. Here are the average sea temperatures.

Best Time

The best time to visit Kolkata is from mid-December to February. In November and in the first half of December, the rains have usually ceased, but every now and then a cyclone can still affect the area. In March, it starts to get very hot.

Kolkata - Weather by month

Based on the period 1991-2020

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January, the coldest month of the year, is generally a warm month. The average temperature is of 19.0 °C (66 °F), with a minimum of 12.5 °C (54.6 °F) and a maximum of 25.4 °C (77.7 °F).
On the coldest nights of the month, the temperature usually drops to around 9 °C (48.5 °F). However, it dropped to 6.6 °C (43.9 °F) in January 2013.
On the warmest days of the month, the temperature usually reaches around 30 °C (85.5 °F). However, it reached 32 °C (89.6 °F) in January 2006.
Precipitation amounts to 12 mm (0.5 in), and all occurs in one day.
The day lasts on average 10 hours and 55 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 63% of the time.
The average humidity is 69%.
The average wind speed is 4 kph (2 mph).
The average sea temperature is of 23.5 °C (74 °F). Therefore, the sea can be considered barely acceptable for swimming.

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February is generally a warm to hot month. The average temperature is of 22.9 °C (73 °F), with a minimum of 16.5 °C (61.6 °F) and a maximum of 29.4 °C (84.9 °F).
On the coldest nights of the month, the temperature usually drops to around 12 °C (53.5 °F). However, it dropped to 9 °C (48.2 °F) in February 1997.
On the warmest days of the month, the temperature usually reaches around 34.5 °C (94 °F). However, it reached 37.3 °C (99.1 °F) in February 2006.
Precipitation amounts to 25 mm (1 in), distributed over 2 days.
The day lasts on average 11 hours and 25 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 66% of the time.
The average humidity is 64%.
The average wind speed is 4 kph (3 mph).
The average sea temperature is of 24 °C (75.5 °F). Therefore, the sea is warm enough for swimming.

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March is generally a very hot month. The average temperature is of 27.6 °C (82 °F), with a minimum of 21.4 °C (70.6 °F) and a maximum of 33.8 °C (92.8 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 16 °C (61 °F). However, it dropped to 13 °C (55.4 °F) in March 2003.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 37.5 °C (99.5 °F). However, it reached 40.4 °C (104.7 °F) in March 2006.
Precipitation amounts to 30 mm (1.2 in), distributed over 2 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 62% of the time.
The average humidity is 61%.
The average wind speed is 6 kph (4 mph).
The average sea temperature is of 26.5 °C (79.5 °F). Therefore, the sea is pleasantly warm and allows long swims.

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April is generally a very hot month. The average temperature is of 30.3 °C (87 °F), with a minimum of 24.6 °C (76.2 °F) and a maximum of 36 °C (96.9 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 20 °C (68.5 °F). However, it dropped to 16.8 °C (62.2 °F) in April 1997.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 39 °C (102.5 °F). However, it reached 41.7 °C (107.1 °F) in April 2016.
Precipitation amounts to 55 mm (2.2 in), distributed over 4 days.
The day lasts on average 12 hours and 40 minutes.
There are on average 8 hours of sunshine per day. So, the sun shines 63% of the time.
The average humidity is 68%.
The average wind speed is 10 kph (6 mph).
The average sea temperature is of 28 °C (82.5 °F). Therefore, the sea is pleasantly warm and allows long swims.

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May, the hottest month of the year, is generally a very hot, muggy month. The average temperature is of 30.8 °C (87 °F), with a minimum of 25.6 °C (78 °F) and a maximum of 36 °C (96.9 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 21 °C (70 °F). However, it dropped to 17 °C (62.6 °F) in May 2000.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 39.5 °C (103 °F). However, it reached 43.1 °C (109.6 °F) in May 2002.
Precipitation amounts to 155 mm (6.1 in), distributed over 7 days.
The day lasts on average 13 hours and 10 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 57% of the time.
The average humidity is 73%. Hence, the air is normally humid.
The average wind speed is 10 kph (6 mph).
The average sea temperature is of 29 °C (84.5 °F). Therefore, the sea is pleasantly warm and allows long swims.

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June is generally a very hot, muggy month. The average temperature is of 30.5 °C (87 °F), with a minimum of 26.4 °C (79.6 °F) and a maximum of 34.6 °C (94.3 °F).
On the coldest nights, the temperature usually drops to around 23 °C (73.5 °F). However, it dropped to 19.6 °C (67.3 °F) in June 2006.
On the warmest days, the temperature usually reaches around 38.5 °C (101.5 °F). However, it reached 42 °C (107.6 °F) in June 1998.
Precipitation amounts to 295 mm (11.6 in), distributed over 13 days.
The day lasts on average 13 hours and 30 minutes. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 4.5 hours of sunshine per day. So, the sun shines 33% of the time.
The average humidity is 80%. Hence, the air is normally humid.
The average wind speed is 8 kph (5 mph).
The average sea temperature is of 29.5 °C (85.5 °F). Therefore, the sea is pleasantly warm and allows long swims.

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July is generally a very hot, muggy month. The average temperature is of 29.8 °C (86 °F), with a minimum of 26.3 °C (79.4 °F) and a maximum of 33.2 °C (91.8 °F).
On the coldest nights of the month, the temperature usually drops to around 24 °C (75.5 °F). However, it dropped to 23.1 °C (73.6 °F) in July 1997.
On the warmest days of the month, the temperature usually reaches around 36.5 °C (97.5 °F). However, it reached 38.6 °C (101.5 °F) in July 2002.
Precipitation amounts to 345 mm (13.6 in), distributed over 17 days.
The day lasts on average 13 hours and 25 minutes.
There are on average 3.5 hours of sunshine per day. So, the sun shines 25% of the time.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is 7 kph (5 mph).
The average sea temperature is of 29 °C (84.5 °F). Therefore, the sea is pleasantly warm and allows long swims.

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August is generally a very hot, muggy month. The average temperature is of 29.6 °C (85 °F), with a minimum of 26.3 °C (79.3 °F) and a maximum of 33 °C (91.4 °F).
On the coldest nights of the month, the temperature usually drops to around 24 °C (75.5 °F). However, it dropped to 22.7 °C (72.9 °F) in August 1999.
On the warmest days of the month, the temperature usually reaches around 36 °C (97 °F). However, it reached 39.6 °C (103.3 °F) in August 2014.
Precipitation amounts to 345 mm (13.6 in), distributed over 17 days.
The day lasts on average 12 hours and 55 minutes.
There are on average 4 hours of sunshine per day. So, the sun shines 29% of the time.
The average humidity is 84%. Hence, the air is normally humid.
The average wind speed is 7 kph (4 mph).
The average sea temperature is of 29 °C (84 °F). Therefore, the sea is pleasantly warm and allows long swims.

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September is generally a very hot, muggy month. The average temperature is of 29.6 °C (85 °F), with a minimum of 25.9 °C (78.7 °F) and a maximum of 33.2 °C (91.8 °F).
On the coldest nights, the temperature usually drops to around 23.5 °C (74 °F). However, it dropped to 22.2 °C (72 °F) in September 2008.
On the warmest days, the temperature usually reaches around 36 °C (97 °F). However, it reached 37.5 °C (99.5 °F) in September 2014.
Precipitation amounts to 305 mm (12 in), distributed over 13 days.
The day lasts on average 12 hours and 10 minutes.
There are on average 4 hours of sunshine per day. So, the sun shines 35% of the time.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is 6 kph (4 mph).
The average sea temperature is of 29 °C (84.5 °F). Therefore, the sea is pleasantly warm and allows long swims.

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October is generally a very hot, muggy month. The average temperature is of 28.1 °C (83 °F), with a minimum of 23.8 °C (74.9 °F) and a maximum of 32.4 °C (90.4 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 19.5 °C (67.5 °F). However, it dropped to 15.7 °C (60.3 °F) in October 2002.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 35.5 °C (95.5 °F). However, it reached 36.6 °C (97.9 °F) in October 2018.
Precipitation amounts to 160 mm (6.3 in), distributed over 7 days.
The day lasts on average 11 hours and 35 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 56% of the time.
The average humidity is 78%. Hence, the air is normally humid.
The average wind speed is 4 kph (3 mph).
The average sea temperature is of 29 °C (84 °F). Therefore, the sea is pleasantly warm and allows long swims.

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November is generally a warm to hot, muggy month. The average temperature is of 24.5 °C (76 °F), with a minimum of 19 °C (66.2 °F) and a maximum of 30 °C (86.1 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 15 °C (58.5 °F). However, it dropped to 12.8 °C (55 °F) in November 1991.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 33 °C (91 °F). However, it reached 34.7 °C (94.5 °F) in November 2009.
Precipitation amounts to 20 mm (0.8 in), and all occurs in one day.
The day lasts on average 11 hours and 0 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 65% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is 3 kph (2 mph).
The average sea temperature is of 27 °C (81 °F). Therefore, the sea is pleasantly warm and allows long swims.

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December is generally a warm month. The average temperature is of 20.2 °C (68 °F), with a minimum of 13.9 °C (57.1 °F) and a maximum of 26.5 °C (79.6 °F).
On the coldest nights of the month, the temperature usually drops to around 10 °C (49.5 °F). However, it dropped to 8.8 °C (47.8 °F) in December 1996.
On the warmest days of the month, the temperature usually reaches around 30 °C (86 °F). However, it reached 32.1 °C (89.8 °F) in December 2015.
Precipitation amounts to only 9 mm (0.4 in), distributed over 0 days.
The day lasts on average 10 hours and 50 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 6.5 hours of sunshine per day. So, the sun shines 61% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is 3 kph (2 mph).
The average sea temperature is of 25 °C (76.5 °F). Therefore, the sea is warm enough for swimming.