Colombo weather by month
Colombo runs from about 26°C in November to 28°C in April, with May the wettest month at 656 mm.
warmest month
April
28°C
coolest month
November
26°C
wettest month
May
656 mm
worst air month
March
36 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 26°C | 138 mm | 296 h | 28 |
| February | 28°C | 38 mm | 334 h | 27 |
| March | 28°C | 80 mm | 358 h | 36 |
| April | 28°C | 177 mm | 314 h | 20 |
| May | 28°C | 656 mm | 241 h | 13 |
| June | 27°C | 356 mm | 285 h | 12 |
| July | 27°C | 316 mm | 278 h | 16 |
| August | 27°C | 334 mm | 269 h | 16 |
| September | 27°C | 310 mm | 292 h | 15 |
| October | 26°C | 411 mm | 248 h | 20 |
| November | 26°C | 354 mm | 216 h | 21 |
| December | 27°C | 130 mm | 301 h | 26 |
About 3,432 hours of sun a year. Roughly 267 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.