| 2023 Hardiness Zone: | Zone 7a: 0°F to 5°F | |
| 2012 Hardiness Zone: | Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 6b: -5F to 0F | |
| Average First Frost Date: | Oct. 21 - Oct. 31 | |
| Average Last Frost Date: | Apr. 11 - Apr. 20 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 59a - Connecticut Valley | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 06516 - West Haven, CT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 21 | 24 | 31 | 40 | 49 | 59 | 65 | 64 | 56 | 45 | 36 | 27 | 43 |
| Avg Max Temp (°F) | 37 | 40 | 48 | 58 | 69 | 78 | 83 | 82 | 74 | 63 | 52 | 42 | 60 |
| Avg Precip (In.) | 4.14 | 3.07 | 4.34 | 4.31 | 4.35 | 3.88 | 4.04 | 4.06 | 4.08 | 4.03 | 4.09 | 3.85 | 48.24 |