| 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: | 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 01519 - Grafton, MA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 14 | 17 | 25 | 35 | 46 | 55 | 60 | 59 | 50 | 39 | 31 | 21 | 38 |
| Avg Max Temp (°F) | 34 | 37 | 46 | 57 | 69 | 77 | 82 | 80 | 72 | 61 | 50 | 39 | 59 |
| Avg Precip (In.) | 4.29 | 3.39 | 4.21 | 4.08 | 3.72 | 3.75 | 3.79 | 4.02 | 3.96 | 4.25 | 4.39 | 3.94 | 47.81 |