Click on a day for an hourly weather forecast
The temperatures in Fredrikstad in September are usually low and can range between 13°C and 16°C.
You can expect about 3 to 8 days of rain in Fredrikstad 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 Fredrikstad in September 2025.
If you’re planning to visit Fredrikstad in the near future, we highly recommend that you review the 14 day weather forecast for Fredrikstad before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 2° / 0° | 6 | 16 | 10 | 103 mm | Awful | Fredrikstad in January |
| February | 1° / -1° | 6 | 13 | 10 | 89 mm | Awful | Fredrikstad in February |
| March | 4° / 1° | 5 | 21 | 5 | 74 mm | Awful | Fredrikstad in March |
| April | 8° / 5° | 4 | 24 | 1 | 52 mm | Ok | Fredrikstad in April |
| May | 12° / 9° | 7 | 24 | 0 | 96 mm | Bad | Fredrikstad in May |
| June | 16° / 13° | 5 | 25 | 0 | 91 mm | Good | Fredrikstad in June |
| July | 18° / 16° | 8 | 23 | 0 | 138 mm | Ok | Fredrikstad in July |
| August | 18° / 15° | 8 | 23 | 0 | 169 mm | Ok | Fredrikstad in August |
| September | 16° / 13° | 7 | 23 | 0 | 143 mm | Ok | Fredrikstad in September |
| October | 11° / 9° | 10 | 21 | 0 | 149 mm | Bad | Fredrikstad in October |
| November | 7° / 5° | 9 | 19 | 2 | 146 mm | Awful | Fredrikstad in November |
| December | 4° / 2° | 9 | 15 | 7 | 121 mm | Awful | Fredrikstad in December |