| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 6b: -5°F to 0°F Zone 4b: -25°F to -20°F Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F | |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 6b: -5°F to 0°F Zone 4b: -25°F to -20°F Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F | |
| Average First Frost Date: | Sep.1 - Sep. 10 | |
| Average Last Frost Date: | Jun. 1 - Jun. 10 | |
| Koppen-Geiger Climate Zone: | Dsb - Humid Continental Climate - Dry Cool Summer | |
| Ecoregion: | 15q - Purcell-Cabinet-North Bitterroot Mountains | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 59935 - Troy, MT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 20 | 23 | 27 | 33 | 40 | 46 | 50 | 49 | 41 | 34 | 28 | 21 | 34 |
| Avg Max Temp (°F) | 32 | 39 | 48 | 59 | 68 | 75 | 83 | 83 | 73 | 57 | 40 | 32 | 57 |
| Avg Precip (In.) | 2.86 | 2.21 | 1.86 | 1.6 | 1.94 | 1.93 | 1.35 | 1.23 | 1.38 | 1.91 | 3.51 | 3.14 | 24.91 |