Weather in Big Sky: September
| Average day temperature: | 67.1°F | |
| Average night temperature: | 49.5°F | |
| Number of sunny days: | 19 days | |
| Day length: | 11.7 - 13.2 hours | |
| Number of rainy days: | 2 days | |
| Precipitation totals: | 1.4 in. | |
| more information | ||
14 days
forecast
forecast
| Big Sky |
weather in
October
October
| Big Sky |
Air temperature in September, °F
Show year:
2025
2024
2023
The highest day temperature during September of 2025 was 74°F. At the same time the lowest night temperature was 41°F. Daily and nightly averages during September were 62.0°F and 50.6°F.
Sunny, partly cloudy and cloudy days
Mostly all days in September are sunny but cloudy days are also possible.
Precipitation total in September, in.
Precipitation total value in Big Sky in September is 1.4 in. Other months of the year show relatively similar values.
Wind speed in September, mph
The average wind speed value in September is 5.2 mph It makes September one of the most windy months of the year.
Average sunny hours
This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in September is: 9.1.
Best time for vacation in Big Sky
Big Sky on a weather map
Places in USA:
Name
°F
24 Hours Forecast
Big Sky
Local time: 22:17
December 05, friday
0000

23°F
N
5 mph
5 mph
0300

25°F
N
4 mph
4 mph
0600

25°F
E
2 mph
2 mph
0900

23°F
N
3 mph
3 mph
1200

27°F
NE
4 mph
4 mph
1500

27°F
NE
6 mph
6 mph
1800

27°F
N
6 mph
6 mph
2100

27°F
N
8 mph
8 mph



























