Click on a day for an hourly weather forecast
The temperatures in Portsmouth in October are usually low and can range between 11°C and 15°C.
You can expect rain for roughly half of the month of October in Portsmouth. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Portsmouth in October 2025.
If you’re planning to visit Portsmouth in the near future, we highly recommend that you review the 14 day weather forecast for Portsmouth before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 8° / 4° | 9 | 19 | 2 | 108 mm | Awful | Portsmouth in January |
| February | 8° / 5° | 8 | 18 | 2 | 88 mm | Awful | Portsmouth in February |
| March | 10° / 5° | 6 | 25 | 1 | 69 mm | Ok | Portsmouth in March |
| April | 12° / 7° | 5 | 25 | 0 | 57 mm | Ok | Portsmouth in April |
| May | 15° / 9° | 5 | 26 | 0 | 69 mm | Good | Portsmouth in May |
| June | 17° / 12° | 5 | 25 | 0 | 89 mm | Good | Portsmouth in June |
| July | 20° / 14° | 5 | 26 | 0 | 79 mm | Good | Portsmouth in July |
| August | 20° / 15° | 5 | 26 | 0 | 82 mm | Good | Portsmouth in August |
| September | 18° / 13° | 5 | 25 | 0 | 68 mm | Good | Portsmouth in September |
| October | 15° / 11° | 8 | 23 | 0 | 126 mm | Ok | Portsmouth in October |
| November | 11° / 8° | 8 | 21 | 0 | 127 mm | Bad | Portsmouth in November |
| December | 9° / 6° | 9 | 21 | 1 | 122 mm | Bad | Portsmouth in December |