Click on a day for an hourly weather forecast
The temperatures in Welwyn Garden City in September are usually low and can range between 12°C and 19°C.
You can expect about 3 to 8 days of rain in Welwyn Garden City 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 Welwyn Garden City in September 2025.
If you’re planning to visit Welwyn Garden City in the near future, we highly recommend that you review the 14 day weather forecast for Welwyn Garden City before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 6° / 2° | 7 | 20 | 4 | 65 mm | Awful | Welwyn Garden City in January |
| February | 8° / 2° | 8 | 15 | 5 | 62 mm | Awful | Welwyn Garden City in February |
| March | 11° / 4° | 5 | 24 | 2 | 52 mm | Bad | Welwyn Garden City in March |
| April | 14° / 5° | 4 | 25 | 1 | 44 mm | Good | Welwyn Garden City in April |
| May | 17° / 8° | 4 | 27 | 0 | 62 mm | Good | Welwyn Garden City in May |
| June | 20° / 11° | 5 | 25 | 0 | 88 mm | Good | Welwyn Garden City in June |
| July | 22° / 13° | 5 | 26 | 0 | 74 mm | Good | Welwyn Garden City in July |
| August | 22° / 14° | 4 | 27 | 0 | 70 mm | Good | Welwyn Garden City in August |
| September | 19° / 12° | 3 | 27 | 0 | 45 mm | Good | Welwyn Garden City in September |
| October | 15° / 9° | 6 | 25 | 0 | 66 mm | Good | Welwyn Garden City in October |
| November | 10° / 6° | 6 | 24 | 0 | 59 mm | Ok | Welwyn Garden City in November |
| December | 7° / 3° | 8 | 20 | 3 | 74 mm | Awful | Welwyn Garden City in December |