Cotonou weather by month
Cotonou runs from about 25°C in August to 30°C in April, with June the wettest month at 163 mm.
warmest month
April
30°C
coolest month
August
25°C
wettest month
June
163 mm
worst air month
January
21 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 28°C | 27 mm | 306 h | 21 |
| February | 29°C | 35 mm | 284 h | 17 |
| March | 29°C | 69 mm | 292 h | 11 |
| April | 30°C | 44 mm | 276 h | 11 |
| May | 29°C | 92 mm | 301 h | 9 |
| June | 27°C | 163 mm | 251 h | 9 |
| July | 26°C | 99 mm | 282 h | 11 |
| August | 25°C | 49 mm | 289 h | 10 |
| September | 26°C | 65 mm | 317 h | 9 |
| October | 27°C | 136 mm | 272 h | 9 |
| November | 28°C | 44 mm | 319 h | 10 |
| December | 29°C | 9 mm | 328 h | 12 |
About 3,517 hours of sun a year. Roughly 84 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 2026-05-24. Full method, licences and the list of sources we rejected are on the methodology page.