Brookfield, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.4 °F (low) to 58.1 °F (high). Annual precipitation averages 48.5 Inches. Brookfield 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.9 °F | 33.6 °F | 3.67 in. |
| February | 15.5 °F | 36.1 °F | 3.25 in. |
| March | 23.8 °F | 44.0 °F | 4.21 in. |
| April | 34.4 °F | 56.9 °F | 4.02 in. |
| May | 45.1 °F | 67.8 °F | 3.59 in. |
| June | 54.4 °F | 76.1 °F | 4.18 in. |
| July | 60.2 °F | 81.2 °F | 4.08 in. |
| August | 58.5 °F | 79.5 °F | 4.37 in. |
| September | 50.8 °F | 72.5 °F | 4.27 in. |
| October | 39.2 °F | 60.5 °F | 4.75 in. |
| November | 30.1 °F | 49.4 °F | 3.71 in. |
| December | 21.6 °F | 39.0 °F | 4.37 in. |
| Annual | 37.4 °F | 58.1 °F | 48.47 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 |