| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F |
| 2012 Hardiness Zone: | Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F |
| 1990 Hardiness Zone: | Zone 4a: -30F to -25F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 21 - May 31 |
| 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 03561 - Littleton, NH | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 5 | 7 | 18 | 30 | 41 | 50 | 55 | 53 | 45 | 35 | 26 | 13 | 32 |
| Avg Max Temp (°F) | 26 | 30 | 40 | 53 | 67 | 75 | 79 | 77 | 68 | 56 | 42 | 30 | 53 |
| Avg Precip (In.) | 2.5 | 1.87 | 2.28 | 2.7 | 3.23 | 4.01 | 4.04 | 4.13 | 3.45 | 3.19 | 3.16 | 2.61 | 37.17 |