Click on a day for an hourly weather forecast
The temperatures in Aalst in September are usually low and can range between 12°C and 20°C.
You can expect about 3 to 8 days of rain in Aalst 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 Aalst in September 2025.
If you’re planning to visit Aalst in the near future, we highly recommend that you review the 14 day weather forecast for Aalst before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 6° / 1° | 9 | 17 | 5 | 104 mm | Awful | Aalst in January |
| February | 7° / 2° | 8 | 15 | 5 | 83 mm | Awful | Aalst in February |
| March | 11° / 4° | 7 | 23 | 2 | 77 mm | Awful | Aalst in March |
| April | 15° / 6° | 4 | 26 | 1 | 43 mm | Good | Aalst in April |
| May | 18° / 9° | 5 | 26 | 0 | 69 mm | Good | Aalst in May |
| June | 21° / 12° | 5 | 25 | 0 | 80 mm | Good | Aalst in June |
| July | 23° / 14° | 4 | 27 | 0 | 67 mm | Perfect | Aalst in July |
| August | 23° / 14° | 5 | 26 | 0 | 78 mm | Perfect | Aalst in August |
| September | 20° / 12° | 3 | 27 | 0 | 42 mm | Good | Aalst in September |
| October | 15° / 9° | 5 | 26 | 0 | 67 mm | Good | Aalst in October |
| November | 10° / 5° | 8 | 22 | 1 | 95 mm | Bad | Aalst in November |
| December | 7° / 3° | 11 | 17 | 3 | 116 mm | Awful | Aalst in December |