WEATHER · CLIMATE NORMALS · 1991–2020
Kolkata Climate — Averages by Month
What the weather in Kolkata, INaverages across a standard 30-year period. Each month's figure is the 1991–2020 mean temperature and total rainfall from the ERA5 reanalysis — the long-run normal a place settles around, not a forecast for any particular day.
Month-by-month normals
| Month | Avg temperature | Avg rainfall |
|---|---|---|
| January | 18.6 °C · coldest | 13.8 mm |
| February | 22.6 °C | 24.7 mm |
| March | 27.1 °C | 31.4 mm |
| April | 29.8 °C | 70.5 mm |
| May | 30.5 °C · warmest | 126.3 mm |
| June | 29.9 °C | 274.5 mm |
| July | 29.0 °C | 356.6 mm · wettest |
| August | 28.8 °C | 317.2 mm |
| September | 28.6 °C | 256.5 mm |
| October | 27.3 °C | 136.2 mm |
| November | 23.8 °C | 29.6 mm |
| December | 19.7 °C | 10.6 mm |
How to read these numbers
These are reanalysis normals, not readings from a single weather station. They come from the ERA5 0.25° (~25 km) global reanalysis grid, sampled at the grid cell nearest Kolkata — centred at 22.50°N, 88.25°E. A reanalysis blends observations with a physics model onto an even grid, so a coastal or mountain city's cell can read a little cooler, warmer, wetter or drier than the city centre itself. The month-to-month shape — when it's hot, when it rains — is what these normals capture best.
“Normal” means the 1991–2020 average, the current World Meteorological Organization standard period. A normal is what a place tends toward over decades — any single day, month or year can and will depart from it.