Click on a day for an hourly weather forecast
The temperatures in Ascona in September are usually low and can range between 10°C and 18°C.
You can expect about 3 to 8 days of rain in Ascona during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Ascona in September 2026.
If you’re planning to visit Ascona in the near future, we highly recommend that you review the 14 day weather forecast for Ascona before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 3° / -2° | 4 | 16 | 11 | 50 mm | Awful | Ascona in January |
| February | 4° / -2° | 5 | 12 | 12 | 56 mm | Awful | Ascona in February |
| March | 8° / 1° | 5 | 17 | 10 | 83 mm | Bad | Ascona in March |
| April | 12° / 4° | 7 | 19 | 5 | 156 mm | Awful | Ascona in April |
| May | 16° / 7° | 10 | 21 | 0 | 178 mm | Ok | Ascona in May |
| June | 20° / 11° | 10 | 20 | 0 | 169 mm | Ok | Ascona in June |
| July | 22° / 13° | 10 | 21 | 0 | 157 mm | Ok | Ascona in July |
| August | 22° / 13° | 8 | 23 | 0 | 152 mm | Ok | Ascona in August |
| September | 18° / 10° | 4 | 26 | 0 | 88 mm | Good | Ascona in September |
| October | 13° / 6° | 4 | 26 | 2 | 157 mm | Bad | Ascona in October |
| November | 8° / 3° | 7 | 16 | 7 | 212 mm | Awful | Ascona in November |
| December | 4° / -1° | 3 | 16 | 12 | 77 mm | Awful | Ascona in December |