Click on a day for an hourly weather forecast
The temperatures in London 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 London 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 London in September 2025.
If you’re planning to visit London in the near future, we highly recommend that you review the 14 day weather forecast for London before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 7° / 3° | 8 | 19 | 4 | 81 mm | Awful | London in January |
| February | 8° / 3° | 8 | 16 | 4 | 75 mm | Awful | London in February |
| March | 10° / 4° | 5 | 24 | 2 | 56 mm | Bad | London in March |
| April | 14° / 6° | 4 | 26 | 1 | 44 mm | Good | London in April |
| May | 16° / 8° | 6 | 26 | 0 | 66 mm | Good | London in May |
| June | 19° / 11° | 5 | 25 | 0 | 77 mm | Good | London in June |
| July | 22° / 14° | 5 | 26 | 0 | 70 mm | Good | London in July |
| August | 21° / 14° | 4 | 27 | 0 | 77 mm | Good | London in August |
| September | 19° / 12° | 4 | 26 | 0 | 51 mm | Good | London in September |
| October | 15° / 10° | 7 | 24 | 0 | 90 mm | Ok | London in October |
| November | 11° / 6° | 7 | 22 | 1 | 82 mm | Bad | London in November |
| December | 8° / 4° | 8 | 21 | 3 | 90 mm | Awful | London in December |