Click on a day for an hourly weather forecast
The temperatures in Basel in September are comfortable with low of 10°C and and high up to 21°C.
You can expect about 3 to 8 days of rain in Basel 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 Basel in September 2025.
If you’re planning to visit Basel in the near future, we highly recommend that you review the 14 day weather forecast for Basel before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 5° / -1° | 9 | 13 | 10 | 105 mm | Awful | Basel in January |
| February | 6° / -1° | 8 | 12 | 9 | 94 mm | Awful | Basel in February |
| March | 11° / 2° | 8 | 19 | 4 | 84 mm | Awful | Basel in March |
| April | 15° / 5° | 6 | 23 | 1 | 87 mm | Good | Basel in April |
| May | 18° / 8° | 10 | 21 | 0 | 157 mm | Ok | Basel in May |
| June | 22° / 11° | 9 | 21 | 0 | 176 mm | Ok | Basel in June |
| July | 24° / 13° | 8 | 23 | 0 | 168 mm | Good | Basel in July |
| August | 25° / 13° | 8 | 23 | 0 | 140 mm | Good | Basel in August |
| September | 21° / 10° | 5 | 25 | 0 | 79 mm | Good | Basel in September |
| October | 16° / 7° | 6 | 25 | 0 | 98 mm | Good | Basel in October |
| November | 10° / 3° | 8 | 20 | 2 | 110 mm | Awful | Basel in November |
| December | 6° / 0° | 11 | 13 | 7 | 136 mm | Awful | Basel in December |