| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F | |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F | |
| Average First Frost Date: | Sep. 21 - Sep. 30 | |
| Average Last Frost Date: | May 21 - May 31 | |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year | |
| Ecoregion: | 15e - Flathead Hills and Mountains | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 59910 - Big Arm, MT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 18 | 21 | 26 | 32 | 39 | 46 | 51 | 50 | 42 | 34 | 26 | 20 | 34 |
| Avg Max Temp (°F) | 32 | 37 | 46 | 57 | 66 | 73 | 82 | 82 | 71 | 57 | 40 | 32 | 56 |
| Avg Precip (In.) | 1.03 | 1.06 | 1.06 | 1.28 | 2.25 | 1.97 | 1.34 | 1.06 | 1.24 | .95 | 1.36 | 1.13 | 15.75 |