| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F | |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F 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: | May 1 - May 10 | |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year | |
| 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 06423 - East Haddam, CT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 18 | 19 | 27 | 35 | 45 | 55 | 61 | 59 | 52 | 40 | 33 | 23 | 39 |
| Avg Max Temp (°F) | 37 | 39 | 47 | 58 | 69 | 78 | 82 | 81 | 73 | 63 | 52 | 41 | 60 |
| Avg Precip (In.) | 4.82 | 3.51 | 4.62 | 4.61 | 4.19 | 4.1 | 3.89 | 4.55 | 4.18 | 4.57 | 4.76 | 4.44 | 52.24 |