Ashby, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.1 °F (low) to 56.2 °F (high). Annual precipitation averages 50 Inches. Ashby is located in USDA Plant Hardiness Zone 6a. 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 | 13.3 °F | 31.0 °F | 3.66 in. |
| February | 14.6 °F | 34.1 °F | 3.39 in. |
| March | 22.3 °F | 41.7 °F | 4.39 in. |
| April | 33.3 °F | 55.0 °F | 4.19 in. |
| May | 43.8 °F | 66.3 °F | 3.93 in. |
| June | 53.2 °F | 74.9 °F | 4.37 in. |
| July | 58.7 °F | 80.0 °F | 4.07 in. |
| August | 56.9 °F | 78.5 °F | 4.05 in. |
| September | 49.7 °F | 71.4 °F | 4.22 in. |
| October | 38.6 °F | 58.6 °F | 5.15 in. |
| November | 29.1 °F | 47.0 °F | 3.98 in. |
| December | 20.1 °F | 36.4 °F | 4.59 in. |
| Annual | 36.1 °F | 56.2 °F | 49.99 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |