| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| 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: | 58g - Worcester/Monadnock Plateau |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 03465 - Troy, NH | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 7 | 10 | 20 | 30 | 41 | 49 | 54 | 53 | 44 | 33 | 26 | 15 | 32 |
| Avg Max Temp (°F) | 30 | 33 | 42 | 54 | 66 | 74 | 80 | 77 | 69 | 57 | 45 | 34 | 55 |
| Avg Precip (In.) | 3.84 | 2.96 | 3.73 | 3.76 | 4.08 | 3.84 | 4.08 | 4.2 | 3.73 | 3.85 | 3.96 | 3.65 | 45.68 |