| 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 11 - May 20 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 59c - Southern New England Coastal Plains and Hills | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 06759 - Litchfield, CT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 12 | 14 | 23 | 33 | 43 | 52 | 58 | 56 | 48 | 37 | 29 | 19 | 35 |
| Avg Max Temp (°F) | 33 | 35 | 45 | 57 | 68 | 76 | 81 | 79 | 71 | 60 | 49 | 37 | 57 |
| Avg Precip (In.) | 4.51 | 3.36 | 4.75 | 4.32 | 4.57 | 4.42 | 4.58 | 4.87 | 4.92 | 4.72 | 4.65 | 4.34 | 54.01 |