| 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 5a: -20°F to -15°F Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F | |
| 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 | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 03244 - Hillsborough, NH | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 12 | 14 | 23 | 33 | 44 | 53 | 58 | 56 | 48 | 38 | 29 | 18 | 36 |
| Avg Max Temp (°F) | 30 | 33 | 42 | 55 | 67 | 75 | 79 | 77 | 69 | 58 | 45 | 34 | 55 |
| Avg Precip (In.) | 3.84 | 2.91 | 3.94 | 3.68 | 4.04 | 3.79 | 3.61 | 3.56 | 3.65 | 3.96 | 4.04 | 3.63 | 44.63 |