| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°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: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 59a - Connecticut Valley |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 06006 - Windsor, CT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 17 | 19 | 28 | 38 | 48 | 57 | 63 | 61 | 52 | 40 | 33 | 23 | 40 |
| Avg Max Temp (°F) | 35 | 38 | 47 | 59 | 71 | 79 | 84 | 82 | 74 | 63 | 51 | 40 | 60 |
| Avg Precip (In.) | 3.87 | 2.91 | 3.9 | 4.01 | 4.13 | 3.91 | 3.87 | 3.95 | 4.06 | 4 | 3.98 | 3.65 | 46.23 |