| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°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: | Apr. 21 - Apr. 30 | |
| 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 06333 - East Lyme, CT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 19 | 21 | 28 | 37 | 47 | 56 | 62 | 61 | 53 | 42 | 34 | 25 | 40 |
| Avg Max Temp (°F) | 38 | 40 | 48 | 58 | 68 | 77 | 82 | 80 | 73 | 63 | 53 | 42 | 60 |
| Avg Precip (In.) | 4.59 | 3.63 | 4.65 | 4.43 | 4.03 | 3.74 | 3.58 | 4.43 | 4.12 | 4.31 | 4.72 | 4.48 | 50.72 |