| 2023 Hardiness Zone: | 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 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: | 58f - Vermont Piedmont | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 03602 - Alstead, NH | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 9 | 11 | 21 | 32 | 43 | 52 | 57 | 56 | 47 | 36 | 28 | 16 | 34 |
| Avg Max Temp (°F) | 30 | 34 | 43 | 55 | 68 | 76 | 81 | 79 | 70 | 59 | 46 | 35 | 56 |
| Avg Precip (In.) | 3.29 | 2.53 | 3.18 | 3.25 | 3.8 | 3.56 | 3.88 | 3.62 | 3.36 | 3.47 | 3.46 | 3.06 | 40.46 |