Biarritz weather by month
Biarritz runs from about 9°C in January to 21°C in August, with March the wettest month at 242 mm.
warmest month
August
21°C
coolest month
January
9°C
wettest month
March
242 mm
worst air month
March
9 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 9°C | 97 mm | 186 h | 5 |
| February | 11°C | 197 mm | 155 h | 5 |
| March | 12°C | 242 mm | 262 h | 9 |
| April | 14°C | 119 mm | 301 h | 7 |
| May | 15°C | 140 mm | 338 h | 6 |
| June | 18°C | 123 mm | 303 h | 7 |
| July | 21°C | 41 mm | 352 h | 5 |
| August | 21°C | 55 mm | 344 h | 7 |
| September | 17°C | 237 mm | 286 h | 5 |
| October | 17°C | 182 mm | 206 h | 6 |
| November | 13°C | 112 mm | 203 h | 4 |
| December | 9°C | 152 mm | 172 h | 8 |
About 3,108 hours of sun a year. Roughly 170 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.