| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F | |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 4a: -30F to -25F | |
| 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: | 17s - Bitterroot-Frenchtown Valley | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 8 - 14 days Over 86°F |
Annual Climate Data for ZIP Code 59801 - Missoula, MT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 16 | 21 | 27 | 32 | 39 | 46 | 50 | 49 | 41 | 32 | 24 | 17 | 33 |
| Avg Max Temp (°F) | 31 | 38 | 48 | 58 | 66 | 74 | 83 | 83 | 72 | 57 | 40 | 31 | 57 |
| Avg Precip (In.) | 1.06 | .78 | .97 | 1.11 | 1.96 | 1.76 | 1.1 | 1.16 | 1.09 | .85 | .97 | 1.14 | 13.95 |