Littleton Common, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.3 °F (low) to 59.7 °F (high). Annual precipitation averages 48.5 Inches. Littleton Common 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 | 15.3 °F | 34.6 °F | 3.62 in. |
| February | 17.0 °F | 37.3 °F | 3.39 in. |
| March | 25.0 °F | 45.1 °F | 4.37 in. |
| April | 35.6 °F | 58.3 °F | 4.17 in. |
| May | 46.2 °F | 69.1 °F | 3.79 in. |
| June | 55.7 °F | 77.8 °F | 4.41 in. |
| July | 61.3 °F | 83.6 °F | 3.7 in. |
| August | 59.7 °F | 82.1 °F | 3.86 in. |
| September | 51.5 °F | 75.0 °F | 3.91 in. |
| October | 39.8 °F | 62.5 °F | 4.85 in. |
| November | 30.4 °F | 51.0 °F | 3.85 in. |
| December | 21.8 °F | 40.4 °F | 4.58 in. |
| Annual | 38.3 °F | 59.7 °F | 48.5 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 6a : -10°F to -5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |