| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 1 - May 10 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 58e - Berkshire Transition |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 06063 - Barkhamsted, CT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 13 | 15 | 24 | 34 | 45 | 54 | 59 | 57 | 49 | 38 | 30 | 20 | 37 |
| Avg Max Temp (°F) | 33 | 36 | 45 | 56 | 69 | 77 | 82 | 79 | 71 | 60 | 49 | 38 | 58 |
| Avg Precip (In.) | 4.12 | 3.22 | 4.3 | 4.26 | 4.52 | 4.31 | 4.27 | 4.48 | 4.53 | 4.33 | 4.23 | 3.98 | 50.56 |