Kolkata has a tropical wet-and-dry climate (Köppen Aw) with three distinct seasons: a hot, humid summer (March-May), a monsoon season (June-September) that delivers 1,582mm of annual rainfall, and a mild, dry winter (November-February). The Bay of Bengal drives humidity levels above 70% year-round, peaking at 85% in August. Kolkata sits just 9 metres above sea level on the Ganges Delta, making the heat feel more oppressive than temperature readings suggest.
Kolkata Weather in January
January is the coldest and driest month. Daytime highs average 26°C (79°F) with nighttime lows dropping to 13°C (55°F). Rainfall is just 10mm over 1 rainy day. Humidity sits at 64%, the lowest of the year. Seven hours of sunshine. This is Kolkata’s most comfortable month for walking the Maidan and Park Street areas. Mornings can have light fog from the Hooghly River.
Kolkata Weather in February
February warms slightly: highs of 29°C (84°F), lows of 16°C (61°F). Rainfall is 22mm over 2 days. Humidity is 60%. Eight hours of sunshine. This is still peak tourist season. The Kolkata Book Fair typically runs late January into early February.
Kolkata Weather in March
March is the start of the hot season. Highs reach 34°C (93°F) and lows 21°C (70°F). Rainfall is 34mm over 3 days. Humidity rises to 60%. Eight hours of sunshine. Afternoons become uncomfortably hot for outdoor sightseeing. The Holi festival falls in March, celebrated across the Kolkata neighborhoods.
Kolkata Weather in April
April brings oppressive pre-monsoon heat. Highs average 36°C (97°F) and lows 25°C (77°F). Rainfall is 54mm over 4 days. Humidity climbs to 70%. Nine hours of sunshine but the heat index (feels-like temperature) regularly exceeds 42°C (108°F). Limit outdoor activities to before 10:00 and after 16:00. Air conditioning becomes essential in your Kolkata accommodation.
Kolkata Weather in May
May is the hottest month. Highs hit 37°C (99°F) and lows 26°C (79°F). Rainfall increases to 118mm over 8 days as pre-monsoon storms (Kal Baisakhi or nor’westers) arrive in the afternoons. Humidity reaches 75%. These sudden electrical storms bring brief relief from the heat but can cause local flooding. Eight hours of sunshine. The worst month to visit Kolkata for comfort.
Kolkata Weather in June
June marks the monsoon onset. Highs drop slightly to 34°C (93°F) and lows to 27°C (81°F). Rainfall jumps to 288mm over 14 rainy days. Humidity spikes to 80%. Five hours of sunshine. The monsoon typically arrives around June 10-15. Streets flood regularly after heavy downpours. Indoor attractions like the Indian Museum become the default activity.
Kolkata Weather in July
July is the wettest month. Highs reach 32°C (90°F) and lows 26°C (79°F). Rainfall totals 345mm over 18 rainy days, the annual peak. Humidity at 83%. Four hours of sunshine. Persistent rain and waterlogged streets make sightseeing difficult. Umbrellas are useless in monsoon downpours; buy a lightweight poncho from New Market (50-100 INR).
Kolkata Weather in August
August is nearly as wet as July. Highs average 32°C (90°F) and lows 26°C (79°F). Rainfall is 332mm over 17 rainy days. Humidity peaks at 85%, the year’s highest. Four hours of sunshine. Independence Day (August 15) celebrations at the Red Road add a reason to visit despite the rain. Mosquitoes are at their worst; carry repellent.
Kolkata Weather in September
September sees the monsoon begin to retreat. Highs of 32°C (90°F) and lows of 26°C (79°F). Rainfall drops to 284mm over 13 days. Humidity stays at 83%. Five hours of sunshine. The Durga Puja preparations begin across the city, with artisans constructing pandals (temporary temples) in Kumartuli.
Kolkata Weather in October
October is the post-monsoon transition. Highs drop to 32°C (90°F) and lows to 23°C (73°F). Rainfall falls sharply to 131mm over 6 days. Humidity eases to 75%. Seven hours of sunshine. The month’s highlight is Durga Puja, Kolkata’s largest festival, usually falling in October, when the city transforms with thousands of illuminated pandals. This is the busiest tourist period despite the higher hotel rates during the festival.
Kolkata Weather in November
November marks winter’s return. Highs reach 29°C (84°F) and lows drop to 18°C (64°F). Rainfall is just 14mm over 1 rainy day. Humidity drops to 66%. Seven hours of sunshine. This is the most comfortable month, combining warm-but-not-hot temperatures with dry skies. Hotel prices are moderate between Durga Puja and Christmas peaks.
Kolkata Weather in December
December is the second-coolest month. Highs average 26°C (79°F) and lows dip to 13°C (55°F). Rainfall is just 5mm over 1 rainy day. Humidity at 65%. Seven hours of sunshine. Christmas on Park Street draws large crowds for the street illuminations. Peak tourist season with the highest hotel rates outside Durga Puja.
Kolkata Monthly Weather Comparison
| Month | Avg High (°C/°F) | Avg Low (°C/°F) | Rainfall (mm) | Rain Days | Sun (hrs) | Humidity |
|---|---|---|---|---|---|---|
| Jan | 26 / 79 | 13 / 55 | 10 | 1 | 7 | 64% |
| Feb | 29 / 84 | 16 / 61 | 22 | 2 | 8 | 60% |
| Mar | 34 / 93 | 21 / 70 | 34 | 3 | 8 | 60% |
| Apr | 36 / 97 | 25 / 77 | 54 | 4 | 9 | 70% |
| May | 37 / 99 | 26 / 79 | 118 | 8 | 8 | 75% |
| Jun | 34 / 93 | 27 / 81 | 288 | 14 | 5 | 80% |
| Jul | 32 / 90 | 26 / 79 | 345 | 18 | 4 | 83% |
| Aug | 32 / 90 | 26 / 79 | 332 | 17 | 4 | 85% |
| Sep | 32 / 90 | 26 / 79 | 284 | 13 | 5 | 83% |
| Oct | 32 / 90 | 23 / 73 | 131 | 6 | 7 | 75% |
| Nov | 29 / 84 | 18 / 64 | 14 | 1 | 7 | 66% |
| Dec | 26 / 79 | 13 / 55 | 5 | 1 | 7 | 65% |
