Click on a day for an hourly weather forecast
The temperatures in Southampton in September are usually low and can range between 14°C and 18°C.
You can expect about 3 to 8 days of rain in Southampton 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 Southampton in September 2025.
If you’re planning to visit Southampton in the near future, we highly recommend that you review the 14 day weather forecast for Southampton before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 8° / 5° | 9 | 20 | 3 | 111 mm | Awful | Southampton in January |
| February | 8° / 5° | 9 | 17 | 3 | 89 mm | Awful | Southampton in February |
| March | 10° / 6° | 6 | 25 | 1 | 65 mm | Ok | Southampton in March |
| April | 12° / 7° | 4 | 25 | 0 | 53 mm | Ok | Southampton in April |
| May | 14° / 9° | 4 | 27 | 0 | 60 mm | Good | Southampton in May |
| June | 17° / 12° | 5 | 25 | 0 | 79 mm | Good | Southampton in June |
| July | 19° / 14° | 4 | 27 | 0 | 71 mm | Good | Southampton in July |
| August | 19° / 15° | 4 | 27 | 0 | 80 mm | Good | Southampton in August |
| September | 18° / 14° | 4 | 26 | 0 | 67 mm | Good | Southampton in September |
| October | 15° / 12° | 8 | 23 | 0 | 131 mm | Ok | Southampton in October |
| November | 12° / 9° | 8 | 21 | 0 | 129 mm | Bad | Southampton in November |
| December | 9° / 7° | 8 | 21 | 1 | 125 mm | Bad | Southampton in December |