Cayenne weather by month
Cayenne runs from about 26°C in June to 28°C in October, with May the wettest month at 678 mm.
warmest month
October
28°C
coolest month
June
26°C
wettest month
May
678 mm
worst air month
February
14 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 27°C | 219 mm | 299 h | 7 |
| February | 27°C | 139 mm | 315 h | 14 |
| March | 27°C | 174 mm | 293 h | 6 |
| April | 27°C | 427 mm | 253 h | 8 |
| May | 26°C | 678 mm | 208 h | 7 |
| June | 26°C | 410 mm | 258 h | 4 |
| July | 26°C | 300 mm | 319 h | 4 |
| August | 27°C | 121 mm | 353 h | 5 |
| September | 28°C | 35 mm | 341 h | 7 |
| October | 28°C | 88 mm | 337 h | 5 |
| November | 27°C | 183 mm | 300 h | 4 |
| December | 26°C | 406 mm | 240 h | 5 |
About 3,516 hours of sun a year. Roughly 246 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.