Great Falls in September
8.3out of 10
Yes, a good time to go
Warm and comfortable: highs around 23°C. Some rain: about 6 rainy days.
23°CAvg high
9°CAvg low
6Rainy days (36 mm)
12:19 hDaylight
07:10Sunrise · 19:29 Sunset
Why this score
- Warm and comfortable: highs around 23°C
- Some rain: about 6 rainy days
What to wear and pack
- T-shirts and light layers
- A light jacket for cooler evenings
How reliable is the forecast?
Rainfall in September is fairly consistent from year to year (2.6 days). Averages cover 30 years (1991–2020). Individual days can differ a lot.
Year at a glance
Weather by month
| Month | Avg high | Avg low | Rainfall | Rainy days | Humidity | Sunshine | Score |
|---|---|---|---|---|---|---|---|
| January | 1°C | -7°C | 20 mm | 6 | – | – | 4.4 |
| February | 3°C | -7°C | 19 mm | 6 | – | – | 4.8 |
| March | 9°C | -3°C | 26 mm | 7 | – | – | 5.7 |
| April | 14°C | 2°C | 52 mm | 9 | – | – | 6.5 |
| May | 20°C | 6°C | 61 mm | 11 | – | – | 7.3 |
| June | 24°C | 10°C | 73 mm | 10 | – | – | 7.7 |
| July | 30°C | 14°C | 24 mm | 5 | – | – | 8.1 |
| August | 30°C | 13°C | 28 mm | 5 | – | – | 8.3 |
| September | 23°C | 9°C | 36 mm | 6 | – | – | 8.3 |
| October | 15°C | 3°C | 34 mm | 6 | – | – | 7.1 |
| November | 7°C | -2°C | 23 mm | 6 | – | – | 5.6 |
| December | 1°C | -6°C | 21 mm | 6 | – | – | 4.5 |
Frequently asked questions
How hot is Great Falls in September?
Daytime highs average 23°C and nights about 9°C.
When is the best time to visit Great Falls?
The best months are August, September, July.