Bristol weather by month
Bristol runs from about 5°C in January to 17°C in August, with September the wettest month at 250 mm.
warmest month
August
17°C
coolest month
January
5°C
wettest month
September
250 mm
worst air month
March
11 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 5°C | 69 mm | 133 h | 5 |
| February | 8°C | 155 mm | 96 h | 5 |
| March | 8°C | 123 mm | 186 h | 11 |
| April | 9°C | 77 mm | 239 h | 7 |
| May | 13°C | 104 mm | 312 h | 8 |
| June | 14°C | 38 mm | 359 h | 6 |
| July | 16°C | 83 mm | 311 h | 5 |
| August | 17°C | 70 mm | 280 h | 6 |
| September | 14°C | 250 mm | 201 h | 5 |
| October | 12°C | 98 mm | 169 h | 7 |
| November | 8°C | 94 mm | 100 h | 5 |
| December | 8°C | 80 mm | 68 h | 6 |
About 2,454 hours of sun a year. Roughly 124 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.