Saint-Malo weather by month
Saint-Malo runs from about 7°C in January to 19°C in August, with September the wettest month at 105 mm.
warmest month
August
19°C
coolest month
January
7°C
wettest month
September
105 mm
worst air month
March
10 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 7°C | 80 mm | 154 h | 5 |
| February | 10°C | 97 mm | 112 h | 5 |
| March | 9°C | 73 mm | 223 h | 10 |
| April | 11°C | 51 mm | 267 h | 7 |
| May | 14°C | 49 mm | 343 h | 7 |
| June | 15°C | 32 mm | 373 h | 7 |
| July | 17°C | 64 mm | 300 h | 5 |
| August | 19°C | 78 mm | 319 h | 6 |
| September | 16°C | 105 mm | 243 h | 5 |
| October | 15°C | 89 mm | 224 h | 6 |
| November | 12°C | 80 mm | 103 h | 5 |
| December | 9°C | 68 mm | 97 h | 8 |
About 2,758 hours of sun a year. Roughly 87 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 2026-05-27. Full method, licences and the list of sources we rejected are on the methodology page.