Click on a day for an hourly weather forecast
The temperatures in Cornwall in September are usually low and can range between 14°C and 17°C.
You can expect about 3 to 8 days of rain in Cornwall 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 Cornwall in September 2024.
If you’re planning to visit Cornwall in the near future, we highly recommend that you review the 14 day weather forecast for Cornwall before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 9° / 7° | 10 | 21 | 1 | 145 mm | Bad | Cornwall in January |
| February | 9° / 7° | 9 | 18 | 1 | 119 mm | Bad | Cornwall in February |
| March | 10° / 7° | 7 | 24 | 0 | 92 mm | Bad | Cornwall in March |
| April | 11° / 8° | 5 | 25 | 0 | 70 mm | Ok | Cornwall in April |
| May | 14° / 10° | 5 | 26 | 0 | 72 mm | Good | Cornwall in May |
| June | 16° / 13° | 6 | 24 | 0 | 89 mm | Good | Cornwall in June |
| July | 18° / 15° | 6 | 25 | 0 | 96 mm | Good | Cornwall in July |
| August | 18° / 15° | 7 | 24 | 0 | 119 mm | Ok | Cornwall in August |
| September | 17° / 14° | 5 | 25 | 0 | 79 mm | Good | Cornwall in September |
| October | 15° / 12° | 8 | 23 | 0 | 145 mm | Ok | Cornwall in October |
| November | 12° / 10° | 9 | 21 | 0 | 166 mm | Bad | Cornwall in November |
| December | 10° / 8° | 10 | 20 | 0 | 155 mm | Bad | Cornwall in December |