Average Precipitation for Montana in September
The tables below give monthly averages for rainfall plus snowfall during September at cities, towns and parks in Montana.
Each place has a total for the amount of precipitation it usually receives this month. There is also a count of the number of days with wet weather, when precipitation amounts to 0.01 inches (0.25 millimetres) or more.
The precipitation totals are averages based on weather data collected from 1991 to 2020 for the US National Centers for Environmental Information.
You can jump to a separate table for each region of the state: Northwestern, Southwestern, South - Central and Eastern Montana.
Northwestern Montana
| Days | Place | Inches | Millimetres |
|---|---|---|---|
| 7 | Cut Bank | 1.1 | 27 |
| 7 | Gibson Reservoir Dam | 1.3 | 33 |
| 8 | Kalispell | 1.2 | 30 |
| 7 | Libby | 1.1 | 28 |
| 7 | Missoula | 1.0 | 24 |
| 7 | Polson | 1.2 | 30 |
| 6 | Rogers Pass | 1.7 | 42 |
| 9 | Seeley Lake | 1.2 | 30 |
| 10 | West Glacier | 2.0 | 50 |
| 8 | Whitefish | 1.3 | 32 |
Southwestern Montana
| Days | Place | Inches | Millimetres |
|---|---|---|---|
| 8 | Anaconda | 1.2 | 29 |
| 9 | Bozeman | 1.4 | 37 |
| 7 | Butte | 1.1 | 27 |
| 5 | Dillon | 0.9 | 23 |
| 6 | Hebgen Lake Dam | 1.6 | 40 |
| 6 | Helena | 1.0 | 24 |
| 6 | Sula | 1.3 | 32 |
| 6 | Virginia City | 1.2 | 30 |
South - Central Montana
| Days | Place | Inches | Millimetres |
|---|---|---|---|
| 5 | Bighorn Lake, Yellowtail Dam | 1.7 | 42 |
| 7 | Billings | 1.4 | 35 |
| 10 | Cooke City | 1.7 | 44 |
| 9 | Mystic Lake | 2.0 | 52 |
| 7 | Red Lodge | 1.6 | 41 |
Eastern Montana
| Days | Place | Inches | Millimetres |
|---|---|---|---|
| 6 | Culbertson | 1.3 | 34 |
| 4 | Elwell Lake, Tiber Dam | 0.9 | 23 |
| 6 | Fort Peck Lake Dam | 1.1 | 27 |
| 7 | Glasgow | 1.1 | 27 |
| 7 | Glendive | 1.4 | 36 |
| 7 | Great Falls | 1.3 | 34 |
| 7 | Havre City | 1.1 | 27 |
| 9 | Lewistown | 1.4 | 35 |
| 7 | Miles City | 1.1 | 27 |
Reference
NOAA National Centers for Environmental Information (NCEI). Climate Normals.