Athol, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.3 °C (low) to 14.5 °C (high). Annual precipitation averages 1190.8 Millimeters. Athol is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.8 °C | 0.1 °C | 92.71 mm |
| February | -10.1 °C | 1.8 °C | 76.96 mm |
| March | -5.3 °C | 6.4 °C | 97.28 mm |
| April | 0.8 °C | 13.8 °C | 91.44 mm |
| May | 6.9 °C | 20.4 °C | 88.65 mm |
| June | 12.2 °C | 25.2 °C | 112.78 mm |
| July | 15.2 °C | 28.2 °C | 108.97 mm |
| August | 14.1 °C | 27.3 °C | 107.95 mm |
| September | 9.7 °C | 23.2 °C | 104.9 mm |
| October | 3.3 °C | 15.6 °C | 121.16 mm |
| November | -1.9 °C | 8.9 °C | 91.44 mm |
| December | -6.9 °C | 3.1 °C | 96.52 mm |
| Annual | 2.3 °C | 14.5 °C | 1190.76 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |