Mendon, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.2 °C (low) to 15.6 °C (high). Annual precipitation averages 1262.4 Millimeters. Mendon is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.9 °C | 2.3 °C | 99.31 mm |
| February | -7.2 °C | 3.8 °C | 86.11 mm |
| March | -3 °C | 7.9 °C | 117.86 mm |
| April | 2.6 °C | 14.8 °C | 114.05 mm |
| May | 8.2 °C | 20.6 °C | 89.15 mm |
| June | 13.3 °C | 25.1 °C | 109.47 mm |
| July | 16.7 °C | 28.2 °C | 91.95 mm |
| August | 15.7 °C | 27.4 °C | 103.12 mm |
| September | 11.6 °C | 23.6 °C | 100.84 mm |
| October | 5.2 °C | 17.1 °C | 125.48 mm |
| November | 0.1 °C | 11 °C | 101.85 mm |
| December | -4.6 °C | 5.3 °C | 123.19 mm |
| Annual | 4.2 °C | 15.6 °C | 1262.38 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |