| 2023 Hardiness Zone: | Zone 7a: 0°F to 5°F | |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F | |
| Average First Frost Date: | Oct. 21 - Oct. 31 | |
| 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 06498 - Westbrook, CT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 18 | 20 | 27 | 35 | 45 | 55 | 61 | 60 | 53 | 41 | 33 | 24 | 39 |
| Avg Max Temp (°F) | 38 | 40 | 48 | 58 | 68 | 77 | 82 | 81 | 74 | 64 | 53 | 43 | 60 |
| Avg Precip (In.) | 4.5 | 3.47 | 4.49 | 4.43 | 4.1 | 3.9 | 3.73 | 4.39 | 4.05 | 4.29 | 4.57 | 4.26 | 50.19 |