| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F | |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F | |
| Average First Frost Date: | Aug. 21 - Aug. 31 | |
| Average Last Frost Date: | Jun. 21 - Jun. 30 | |
| 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 59828 - Corvallis, MT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 17 | 21 | 26 | 32 | 38 | 45 | 49 | 47 | 40 | 32 | 24 | 17 | 32 |
| Avg Max Temp (°F) | 35 | 42 | 51 | 60 | 68 | 76 | 84 | 83 | 72 | 60 | 43 | 34 | 59 |
| Avg Precip (In.) | 1.03 | .8 | .81 | .98 | 1.53 | 1.48 | .93 | 1.06 | .93 | .67 | .97 | 1.04 | 12.24 |