Click on a day for an hourly weather forecast
The temperatures in Northumberland in September are comfortable with low of 12°C and and high up to 24°C.
You can expect about 3 to 8 days of rain in Northumberland 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 Northumberland in September 2025.
If you’re planning to visit Northumberland in the near future, we highly recommend that you review the 14 day weather forecast for Northumberland before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 0° / -7° | 7 | 10 | 14 | 55 mm | Awful | Northumberland in January |
| February | 2° / -6° | 7 | 9 | 13 | 64 mm | Awful | Northumberland in February |
| March | 8° / -1° | 7 | 17 | 7 | 66 mm | Awful | Northumberland in March |
| April | 14° / 4° | 7 | 21 | 2 | 83 mm | Bad | Northumberland in April |
| May | 21° / 9° | 7 | 24 | 0 | 99 mm | Ok | Northumberland in May |
| June | 26° / 13° | 6 | 24 | 0 | 93 mm | Perfect | Northumberland in June |
| July | 29° / 16° | 6 | 25 | 0 | 100 mm | Good | Northumberland in July |
| August | 27° / 15° | 5 | 26 | 0 | 84 mm | Perfect | Northumberland in August |
| September | 24° / 12° | 4 | 26 | 0 | 76 mm | Perfect | Northumberland in September |
| October | 17° / 7° | 5 | 26 | 0 | 68 mm | Good | Northumberland in October |
| November | 9° / 1° | 5 | 22 | 3 | 47 mm | Bad | Northumberland in November |
| December | 4° / -2° | 6 | 16 | 9 | 58 mm | Awful | Northumberland in December |