Spencer, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.9 °F (low) to 57.2 °F (high). Annual precipitation averages 49.2 Inches. Spencer is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.3 °F | 32.8 °F | 3.74 in. |
| February | 16.3 °F | 35.4 °F | 3.3 in. |
| March | 24.3 °F | 43.1 °F | 4.35 in. |
| April | 35.0 °F | 55.8 °F | 4.14 in. |
| May | 45.5 °F | 66.8 °F | 3.65 in. |
| June | 55.0 °F | 75.0 °F | 4.25 in. |
| July | 60.6 °F | 80.3 °F | 4.04 in. |
| August | 59.0 °F | 78.7 °F | 4.3 in. |
| September | 51.5 °F | 71.7 °F | 4.24 in. |
| October | 40.1 °F | 59.6 °F | 4.93 in. |
| November | 30.7 °F | 48.7 °F | 3.78 in. |
| December | 22.0 °F | 38.2 °F | 4.45 in. |
| Annual | 37.9 °F | 57.2 °F | 49.17 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |