Weston, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.3 °C (low) to 15.6 °C (high). Annual precipitation averages 1213.4 Millimeters. Weston is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8 °C | 2.1 °C | 92.71 mm |
| February | -7.1 °C | 3.6 °C | 81.53 mm |
| March | -3 °C | 7.7 °C | 110.24 mm |
| April | 2.7 °C | 14.6 °C | 103.38 mm |
| May | 8.2 °C | 20.4 °C | 96.27 mm |
| June | 13.4 °C | 25.2 °C | 108.71 mm |
| July | 16.7 °C | 28.5 °C | 90.42 mm |
| August | 15.9 °C | 27.7 °C | 100.58 mm |
| September | 11.7 °C | 23.9 °C | 93.98 mm |
| October | 5.4 °C | 17.1 °C | 120.65 mm |
| November | 0.2 °C | 10.9 °C | 99.31 mm |
| December | -4.4 °C | 5.2 °C | 115.57 mm |
| Annual | 4.3 °C | 15.6 °C | 1213.35 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |