Otis, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.4 °F (low) to 55.6 °F (high). Annual precipitation averages 55.6 Inches. Otis is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.0 °F | 31.0 °F | 3.89 in. |
| February | 14.0 °F | 33.6 °F | 3.51 in. |
| March | 21.4 °F | 41.5 °F | 4.33 in. |
| April | 31.9 °F | 54.7 °F | 4.38 in. |
| May | 42.8 °F | 66.1 °F | 4.49 in. |
| June | 52.4 °F | 73.7 °F | 5.1 in. |
| July | 57.4 °F | 78.7 °F | 4.85 in. |
| August | 55.9 °F | 77.4 °F | 4.97 in. |
| September | 48.7 °F | 70.2 °F | 5.16 in. |
| October | 38.1 °F | 58.0 °F | 5.7 in. |
| November | 28.6 °F | 46.1 °F | 4.22 in. |
| December | 20.1 °F | 36.0 °F | 4.99 in. |
| Annual | 35.4 °F | 55.6 °F | 55.59 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°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 |