| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F | |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°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: | Dfa - Humid Continental Hot Summers | |
| 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 06483 - Seymour, CT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 18 | 20 | 28 | 37 | 47 | 56 | 62 | 61 | 53 | 42 | 33 | 24 | 40 |
| Avg Max Temp (°F) | 35 | 38 | 47 | 58 | 70 | 78 | 83 | 81 | 73 | 62 | 51 | 40 | 60 |
| Avg Precip (In.) | 4.7 | 3.33 | 4.81 | 4.68 | 4.68 | 4.25 | 4.14 | 4.26 | 4.36 | 4.51 | 4.67 | 4.37 | 52.74 |