Ashfield, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.5 °C (low) to 12.3 °C (high). Annual precipitation averages 1390.9 Millimeters. Ashfield is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.1 °C | -1.4 °C | 97.03 mm |
| February | -10.3 °C | 0.2 °C | 87.88 mm |
| March | -6.3 °C | 4.3 °C | 121.67 mm |
| April | -0.2 °C | 11.3 °C | 118.62 mm |
| May | 5.8 °C | 17.8 °C | 106.43 mm |
| June | 10.9 °C | 22.5 °C | 124.71 mm |
| July | 14.1 °C | 25.4 °C | 115.06 mm |
| August | 13.2 °C | 24.4 °C | 118.62 mm |
| September | 8.9 °C | 20.7 °C | 131.06 mm |
| October | 2.9 °C | 13.6 °C | 139.19 mm |
| November | -2.4 °C | 7.2 °C | 108.97 mm |
| December | -7.6 °C | 1.4 °C | 121.67 mm |
| Annual | 1.5 °C | 12.3 °C | 1390.91 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 125-150 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |