Climate averages 1991–2020
Sankt Gallen weather
in September.
A mild, wet month: the 4th warmest and the 8th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Sankt Gallen: daytime highs average 17.2°C and nights cool to about 9.2°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 127 mm of rain on roughly 14 days, which makes September a wet month (the 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 37 min on an average September day.
The nearest other city in this atlas is Konstanz (30 km away). In September its highs average 18.8°C, 1.6°C warmer than Sankt Gallen, with 94 mm of rain.
Among the 8 cities listed in Switzerland, Sankt Gallen ranks 8th of 8 for the warmest September highs and 7th of 8 for the driest September (rainfall, lowest first). The mean September high of those 8 cities is 18.8°C; Sankt Gallen is 1.6°C cooler than that mean.
From September to October, average highs fall by 3.8°C to 13.4°C, and monthly rainfall falls from 127 mm to 103 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
Sankt Gallen climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 2.8°C-4.8°C | -4.8°C | 88 | 12.7 | 8.99 h |
| February | 3.9°C-4.7°C | -4.7°C | 80 | 11.8 | 10.210 h |
| March | 7.8°C-1.4°C | -1.4°C | 100 | 14.8 | 11.912 h |
| April | 12.0°C2.1°C | 2.1°C | 102 | 14.5 | 13.614 h |
| May | 16.1°C7.0°C | 7.0°C | 155 | 17.2 | 15.115 h |
| June | 19.4°C10.7°C | 10.7°C | 172 | 17.4 | 15.916 h |
| July | 21.3°C12.6°C | 12.6°C | 174 | 17.5 | 15.516 h |
| August | 21.2°C12.7°C | 12.7°C | 175 | 16.8 | 14.314 h |
| September, selected | 17.2°C9.2°C | 9.2°C | 127 | 13.7 | 12.613 h |
| October | 13.4°C5.6°C | 5.6°C | 103 | 12.9 | 10.911 h |
| November | 7.5°C0.4°C | 0.4°C | 103 | 12.7 | 9.49 h |
| December | 3.4°C-3.5°C | -3.5°C | 105 | 14.1 | 8.59 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
- Konstanz in SeptemberGermany · 30 kmHigh 18.8°C · Low 12.9°C · 94 mm rain
- Vaduz in SeptemberLiechtenstein · 33 kmHigh 19.1°C · Low 10.5°C · 154 mm rain
- Winterthur in SeptemberSwitzerland · 50 kmHigh 18.7°C · Low 10.8°C · 91 mm rain
- Zürich in SeptemberSwitzerland · 62 kmHigh 18.9°C · Low 11.2°C · 123 mm rain
- Luzern in SeptemberSwitzerland · 91 kmHigh 18.9°C · Low 11.6°C · 166 mm rain
- Villingen-Schwenningen in SeptemberGermany · 97 kmHigh 16.9°C · Low 8.9°C · 93 mm rain
- Ulm in SeptemberGermany · 118 kmHigh 18.4°C · Low 10.0°C · 69 mm rain
- Reutlingen in SeptemberGermany · 119 kmHigh 19.1°C · Low 10.3°C · 66 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 Sankt Gallen) is explained once on the Sankt Gallen year overview and on the Sources, method and limits page.