Chennai weather by month
Chennai runs from about 26°C in January to 31°C in May, with November the wettest month at 395 mm.
warmest month
May
31°C
coolest month
January
26°C
wettest month
November
395 mm
worst air month
December
38 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 26°C | 52 mm | 307 h | 36 |
| February | 27°C | 6 mm | 330 h | 31 |
| March | 28°C | 5 mm | 362 h | 19 |
| April | 30°C | 1 mm | 353 h | 12 |
| May | 31°C | 188 mm | 283 h | 17 |
| June | 30°C | 165 mm | 256 h | 19 |
| July | 30°C | 80 mm | 209 h | 14 |
| August | 29°C | 146 mm | 288 h | 18 |
| September | 29°C | 121 mm | 268 h | 18 |
| October | 28°C | 253 mm | 299 h | 14 |
| November | 26°C | 395 mm | 241 h | 28 |
| December | 26°C | 200 mm | 262 h | 38 |
About 3,458 hours of sun a year. Roughly 153 rainy days a year.
These are long-run climate normals, not a forecast. A given year can sit well outside them. PM2.5 is a global model: near the coast it counts sea salt as fine particulate and reads high against ground stations, sometimes by a factor of two. Use the shape of the year, not the absolute number.
where these numbers come from
- · Temperature, rainfall and sunshine: ECMWF ERA5 reanalysis climate normals via Open-Meteo (CC BY 4.0), fetched once and stored.
- · PM2.5: Copernicus CAMS reanalysis, monthly means. Modelled, not station readings; near coasts CAMS counts sea salt as PM2.5 and reads high.
Last reviewed 2026-05-23. Full method, licences and the list of sources we rejected are on the methodology page.