| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°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. 11 - Oct. 20 | |
| Average Last Frost Date: | May 1 - May 10 | |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year | |
| Ecoregion: | 58g - Worcester/Monadnock Plateau | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 01541 - Princeton, MA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 14 | 16 | 24 | 34 | 44 | 54 | 59 | 57 | 49 | 38 | 30 | 20 | 37 |
| Avg Max Temp (°F) | 31 | 34 | 42 | 55 | 67 | 75 | 80 | 78 | 70 | 59 | 47 | 36 | 56 |
| Avg Precip (In.) | 4.7 | 3.76 | 4.81 | 4.77 | 4.47 | 4.43 | 4.06 | 4.45 | 4.38 | 4.69 | 4.87 | 4.41 | 53.8 |