| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F |
| Average First Frost Date: | Sep.11 - Sep. 20 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 58n - White Mountain Foothills |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 03574 - Bethlehem, NH | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 6 | 8 | 18 | 30 | 41 | 50 | 55 | 53 | 45 | 35 | 26 | 13 | 32 |
| Avg Max Temp (°F) | 26 | 30 | 40 | 53 | 67 | 75 | 78 | 76 | 67 | 55 | 41 | 30 | 53 |
| Avg Precip (In.) | 2.69 | 1.94 | 2.47 | 2.87 | 3.44 | 4.17 | 4.16 | 4.2 | 3.57 | 3.36 | 3.44 | 2.84 | 39.15 |