| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | Apr. 21 - Apr. 30 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 59a - Connecticut Valley |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 06481 - Rockfall, CT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 20 | 22 | 30 | 39 | 49 | 58 | 63 | 61 | 54 | 43 | 35 | 26 | 41 |
| Avg Max Temp (°F) | 36 | 39 | 47 | 59 | 70 | 79 | 84 | 81 | 73 | 62 | 51 | 41 | 60 |
| Avg Precip (In.) | 4.46 | 3.27 | 4.49 | 4.42 | 4.35 | 4.35 | 4.13 | 4.38 | 4.54 | 4.81 | 4.48 | 4.11 | 51.79 |