| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°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 4a: -30°F to -25°F | |
| 1990 Hardiness Zone: | Zone 3b: -35F to -30F | |
| 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: | 17w - Townsend Basin | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 59752 - Three Forks, MT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 17 | 24 | 31 | 39 | 46 | 50 | 49 | 39 | 31 | 21 | 13 | 31 |
| Avg Max Temp (°F) | 34 | 41 | 49 | 59 | 68 | 77 | 85 | 85 | 74 | 61 | 44 | 35 | 59 |
| Avg Precip (In.) | .38 | .28 | .69 | 1.02 | 2.09 | 1.99 | 1.34 | 1.15 | 1.14 | .84 | .57 | .27 | 11.76 |