Climate averages 1991–2020
Geneva weather
in September.
A mild, wet month: the 4th warmest and the joint 2nd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Geneva: daytime highs average 19.8°C and nights cool to about 11.6°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 109 mm of rain on roughly 12 days, which makes September a wet month (the joint 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 36 min on an average September day.
The nearest other city in this atlas is Lausanne (51 km away). In September its highs average 18.8°C, 1.0°C cooler than Geneva, with 108 mm of rain.
Among the 8 cities listed in Switzerland, Geneva ranks 2nd of 8 for the warmest September highs and 5th of 8 for the driest September (rainfall, lowest first). The mean September high of those 8 cities is 18.8°C; Geneva is 1.0°C warmer than that mean.
From September to October, average highs fall by 4.0°C to 15.8°C, and monthly rainfall rises from 109 mm to 112 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
Geneva climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 5.3°C-0.9°C | -0.9°C | 115 | 12.5 | 9.19 h |
| February | 6.5°C-0.6°C | -0.6°C | 100 | 11.0 | 10.310 h |
| March | 10.8°C2.1°C | 2.1°C | 109 | 12.7 | 11.912 h |
| April | 14.7°C5.4°C | 5.4°C | 109 | 13.5 | 13.514 h |
| May | 18.4°C9.5°C | 9.5°C | 144 | 15.9 | 14.915 h |
| June | 22.0°C13.3°C | 13.3°C | 123 | 14.7 | 15.716 h |
| July | 24.1°C15.5°C | 15.5°C | 123 | 12.8 | 15.415 h |
| August | 24.0°C15.5°C | 15.5°C | 117 | 12.7 | 14.214 h |
| September, selected | 19.8°C11.6°C | 11.6°C | 109 | 12.2 | 12.613 h |
| October | 15.8°C7.5°C | 7.5°C | 112 | 12.4 | 11.011 h |
| November | 9.7°C2.7°C | 2.7°C | 125 | 13.5 | 9.59 h |
| December | 5.9°C-0.1°C | -0.1°C | 131 | 13.4 | 8.79 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
- Lausanne in SeptemberSwitzerland · 51 kmHigh 18.8°C · Low 13.2°C · 108 mm rain
- Villeurbanne in SeptemberFrance · 109 kmHigh 21.8°C · Low 12.9°C · 93 mm rain
- Lyon in SeptemberFrance · 112 kmHigh 22.1°C · Low 12.9°C · 93 mm rain
- Besançon in SeptemberFrance · 117 kmHigh 20.2°C · Low 12.0°C · 93 mm rain
- Grenoble in SeptemberFrance · 119 kmHigh 21.8°C · Low 12.8°C · 111 mm rain
- Bern in SeptemberSwitzerland · 130 kmHigh 17.7°C · Low 9.6°C · 88 mm rain
- Dijon in SeptemberFrance · 151 kmHigh 20.8°C · Low 12.0°C · 75 mm rain
- Saint-Étienne in SeptemberFrance · 161 kmHigh 20.2°C · Low 11.2°C · 90 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 Geneva) is explained once on the Geneva year overview and on the Sources, method and limits page.