Grenchen in September
6.6out of 10
Possible, with caveats
Mild: highs around 18°C. Frequent rain: about 14 rainy days.
18°CAvg high
10°CAvg low
14Rainy days (108 mm)
12:19 hDaylight
07:15Sunrise · 19:34 Sunset
Why this score
- Mild: highs around 18°C
- Frequent rain: about 14 rainy days
What to wear and pack
- Layers you can add or remove
- Rain jacket or compact umbrella
How reliable is the forecast?
Rain in September varies a lot between years (±3.9 rainy days), so check the forecast closer to your trip. Averages cover 30 years (1991–2020). Individual days can differ a lot.
Year at a glance
Weather by month
| Month | Avg high | Avg low | Rainfall | Rainy days | Humidity | Sunshine | Score |
|---|---|---|---|---|---|---|---|
| January | 4°C | -2°C | 83 mm | 13 | – | – | 4.1 |
| February | 5°C | -2°C | 75 mm | 12 | – | – | 4.5 |
| March | 10°C | 1°C | 90 mm | 14 | – | – | 5.1 |
| April | 14°C | 4°C | 103 mm | 16 | – | – | 5.6 |
| May | 18°C | 8°C | 147 mm | 18 | – | – | 5.7 |
| June | 21°C | 12°C | 140 mm | 17 | – | – | 6.4 |
| July | 23°C | 14°C | 146 mm | 17 | – | – | 6.5 |
| August | 23°C | 13°C | 149 mm | 16 | – | – | 6.6 |
| September | 18°C | 10°C | 108 mm | 14 | – | – | 6.6 |
| October | 14°C | 6°C | 101 mm | 13 | – | – | 5.9 |
| November | 8°C | 2°C | 96 mm | 13 | – | – | 4.8 |
| December | 4°C | -1°C | 101 mm | 14 | – | – | 4.0 |
Frequently asked questions
How hot is Grenchen in September?
Daytime highs average 18°C and nights about 10°C.
When is the best time to visit Grenchen?
The best months are August, September, July, June.