Click on a day for an hourly weather forecast
The temperatures in Plymouth in September are comfortable with low of 17°C and and high up to 20°C.
You can expect about 3 to 8 days of rain in Plymouth 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 Plymouth in September 2025.
If you’re planning to visit Plymouth in the near future, we highly recommend that you review the 14 day weather forecast for Plymouth before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 3° / -2° | 6 | 18 | 8 | 92 mm | Awful | Plymouth in January |
| February | 3° / -1° | 6 | 15 | 8 | 91 mm | Awful | Plymouth in February |
| March | 5° / 1° | 6 | 19 | 6 | 94 mm | Awful | Plymouth in March |
| April | 10° / 6° | 6 | 22 | 1 | 86 mm | Ok | Plymouth in April |
| May | 14° / 11° | 6 | 25 | 0 | 89 mm | Good | Plymouth in May |
| June | 19° / 15° | 6 | 24 | 0 | 94 mm | Good | Plymouth in June |
| July | 23° / 20° | 6 | 25 | 0 | 118 mm | Perfect | Plymouth in July |
| August | 23° / 20° | 4 | 27 | 0 | 102 mm | Perfect | Plymouth in August |
| September | 20° / 17° | 4 | 26 | 0 | 79 mm | Good | Plymouth in September |
| October | 16° / 12° | 6 | 25 | 0 | 107 mm | Good | Plymouth in October |
| November | 10° / 7° | 5 | 24 | 1 | 72 mm | Ok | Plymouth in November |
| December | 6° / 2° | 7 | 20 | 5 | 91 mm | Awful | Plymouth in December |