Roseau weather by month
Roseau runs from about 26°C in December to 28°C in October, with November the wettest month at 143 mm.
warmest month
October
28°C
coolest month
December
26°C
wettest month
November
143 mm
worst air month
June
13 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 26°C | 86 mm | 336 h | 6 |
| February | 26°C | 43 mm | 318 h | 9 |
| March | 26°C | 45 mm | 359 h | 7 |
| April | 27°C | 56 mm | 358 h | 7 |
| May | 28°C | 74 mm | 341 h | 11 |
| June | 28°C | 90 mm | 340 h | 13 |
| July | 27°C | 142 mm | 334 h | 11 |
| August | 27°C | 138 mm | 327 h | 9 |
| September | 28°C | 89 mm | 318 h | 6 |
| October | 28°C | 46 mm | 353 h | 7 |
| November | 27°C | 143 mm | 305 h | 7 |
| December | 26°C | 89 mm | 324 h | 6 |
About 4,013 hours of sun a year. Roughly 105 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.