| 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 Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F | |
| Average First Frost Date: | Oct. 1 - Oct. 10 | |
| Average Last Frost Date: | May 21 - May 31 | |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year | |
| Ecoregion: | 59b - Lower Worcester Plateau/Eastern Connecticut Upland | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 01069 - Palmer, MA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 13 | 15 | 24 | 34 | 45 | 54 | 59 | 57 | 49 | 37 | 30 | 20 | 37 |
| Avg Max Temp (°F) | 34 | 37 | 46 | 58 | 70 | 78 | 83 | 81 | 73 | 62 | 50 | 38 | 59 |
| Avg Precip (In.) | 3.93 | 2.94 | 3.9 | 3.98 | 4.01 | 3.94 | 4.16 | 4.25 | 4.05 | 4.07 | 4.04 | 3.65 | 46.92 |