| 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 | |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F | |
| Average First Frost Date: | Aug. 21 - Aug. 31 | |
| Average Last Frost Date: | Jun. 11 - Jun. 20 | |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year | |
| Ecoregion: | 17aa - Dry Intermontane Sagebrush Valleys | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 59754 - Twin Bridges, MT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 15 | 21 | 27 | 35 | 42 | 46 | 43 | 35 | 27 | 19 | 11 | 28 |
| Avg Max Temp (°F) | 34 | 40 | 48 | 58 | 66 | 76 | 83 | 82 | 72 | 60 | 43 | 34 | 58 |
| Avg Precip (In.) | .22 | .18 | .47 | .84 | 1.87 | 1.81 | 1.2 | 1.09 | 1.07 | .62 | .36 | .23 | 9.94 |