| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | October 1 - 10 |
| Average Last Frost Date: | May 11 - 20 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 59b - Lower Worcester Plateau/Eastern Connecticut Upland |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 06076 - Stafford Springs, CT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 14 | 16 | 25 | 34 | 44 | 53 | 58 | 57 | 48 | 37 | 30 | 20 | 36 |
| Avg Max Temp (°F) | 34 | 36 | 45 | 57 | 68 | 76 | 81 | 79 | 71 | 61 | 49 | 39 | 58 |
| Avg Precip (In.) | 4.4 | 3.18 | 4.26 | 4.36 | 4.19 | 4.08 | 4.28 | 4.37 | 4.37 | 4.48 | 4.54 | 4.05 | 50.57 |