Click on a day for an hourly weather forecast
The temperatures in Kalispell in September are quite cold with temperatures between 7°C and 21°C, warm clothes are a must.
You can expect about 3 to 8 days of rain in Kalispell 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 Kalispell in September 2025.
If you’re planning to visit Kalispell in the near future, we highly recommend that you review the 14 day weather forecast for Kalispell before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -3° / -10° | 12 | 12 | 7 | 56 mm | Awful | Kalispell in January |
| February | -2° / -10° | 14 | 8 | 7 | 55 mm | Awful | Kalispell in February |
| March | 4° / -5° | 14 | 12 | 7 | 63 mm | Awful | Kalispell in March |
| April | 9° / -2° | 13 | 13 | 4 | 68 mm | Awful | Kalispell in April |
| May | 17° / 3° | 10 | 21 | 0 | 69 mm | Ok | Kalispell in May |
| June | 21° / 7° | 9 | 21 | 0 | 78 mm | Ok | Kalispell in June |
| July | 27° / 11° | 5 | 26 | 0 | 17 mm | Perfect | Kalispell in July |
| August | 27° / 11° | 4 | 27 | 0 | 31 mm | Perfect | Kalispell in August |
| September | 21° / 7° | 5 | 25 | 0 | 41 mm | Good | Kalispell in September |
| October | 10° / 1° | 9 | 20 | 2 | 70 mm | Awful | Kalispell in October |
| November | 1° / -5° | 14 | 10 | 7 | 66 mm | Awful | Kalispell in November |
| December | -4° / -10° | 16 | 8 | 8 | 66 mm | Awful | Kalispell in December |