Climate averages 1991–2020
Brest, France weather
in September.
A mild, moderately wet month: the 3rd warmest and the 3rd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Brest, France: daytime highs average 17.8°C and nights cool to about 13.6°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 52 mm of rain on roughly 10 days, which makes September a moderately wet month (the 3rd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 38 min on an average September day.
The nearest other city in this atlas is Saint Helier (196 km away). In September its highs average 17.5°C, about as warm as Brest, France, with 77 mm of rain.
Among the 57 cities listed in France, Brest, France ranks 57th of 57 for the warmest September highs and joint 21st of 57 for the driest September (rainfall, lowest first). The mean September high of those 57 cities is 21.3°C; Brest, France is 3.5°C cooler than that mean.
From September to October, average highs fall by 2.6°C to 15.2°C, and monthly rainfall rises from 52 mm to 92 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Brest, France climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 9.7°C6.7°C | 6.7°C | 99 | 15.3 | 8.89 h |
| February | 9.6°C6.2°C | 6.2°C | 80 | 13.4 | 10.210 h |
| March | 10.9°C7.1°C | 7.1°C | 64 | 12.6 | 11.912 h |
| April | 12.5°C8.2°C | 8.2°C | 66 | 11.9 | 13.614 h |
| May | 15.0°C10.6°C | 10.6°C | 59 | 10.5 | 15.215 h |
| June | 17.3°C12.9°C | 12.9°C | 47 | 9.7 | 16.016 h |
| July | 18.9°C14.6°C | 14.6°C | 45 | 10.1 | 15.716 h |
| August | 19.1°C14.9°C | 14.9°C | 53 | 10.0 | 14.314 h |
| September, selected | 17.8°C13.6°C | 13.6°C | 52 | 9.6 | 12.613 h |
| October | 15.2°C11.8°C | 11.8°C | 92 | 14.1 | 10.911 h |
| November | 12.3°C9.5°C | 9.5°C | 96 | 14.9 | 9.39 h |
| December | 10.4°C7.4°C | 7.4°C | 105 | 15.3 | 8.48 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Saint Helier in SeptemberJersey · 196 kmHigh 17.5°C · Low 15.1°C · 77 mm rain
- Rennes in SeptemberFrance · 210 kmHigh 20.5°C · Low 12.2°C · 49 mm rain
- Plymouth in SeptemberUnited Kingdom · 222 kmHigh 17.4°C · Low 12.5°C · 61 mm rain
- Nantes in SeptemberFrance · 255 kmHigh 21.3°C · Low 13.0°C · 49 mm rain
- Exeter in SeptemberUnited Kingdom · 269 kmHigh 17.5°C · Low 11.5°C · 53 mm rain
- Angers in SeptemberFrance · 310 kmHigh 21.3°C · Low 12.6°C · 50 mm rain
- Caen in SeptemberFrance · 315 kmHigh 19.8°C · Low 12.4°C · 53 mm rain
- Poole in SeptemberUnited Kingdom · 315 kmHigh 18.0°C · Low 13.0°C · 54 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Brest) is explained once on the Brest, France year overview and on the Sources, method and limits page.