Stow, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.7 °F (low) to 59.8 °F (high). Annual precipitation averages 49 Inches. Stow is located in USDA Plant Hardiness Zone 6b. 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 | 16.0 °F | 34.8 °F | 3.69 in. |
| February | 17.6 °F | 37.7 °F | 3.42 in. |
| March | 25.5 °F | 45.3 °F | 4.45 in. |
| April | 35.9 °F | 58.4 °F | 4.36 in. |
| May | 46.4 °F | 68.9 °F | 3.75 in. |
| June | 55.8 °F | 77.4 °F | 4.41 in. |
| July | 61.6 °F | 83.4 °F | 3.72 in. |
| August | 60.1 °F | 81.9 °F | 3.86 in. |
| September | 51.8 °F | 74.9 °F | 3.9 in. |
| October | 40.5 °F | 62.7 °F | 4.88 in. |
| November | 30.9 °F | 51.3 °F | 3.81 in. |
| December | 22.5 °F | 40.7 °F | 4.71 in. |
| Annual | 38.7 °F | 59.8 °F | 48.96 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 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |