Smith Mills, Massachusetts has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.2 °C (low) to 15.6 °C (high). Annual precipitation averages 1302 Millimeters. Smith Mills is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.4 °C | 3.4 °C | 112.78 mm |
| February | -4.8 °C | 4.4 °C | 96.27 mm |
| March | -1.3 °C | 7.9 °C | 141.99 mm |
| April | 4.1 °C | 13.8 °C | 115.06 mm |
| May | 9.3 °C | 19.3 °C | 90.17 mm |
| June | 14.6 °C | 24.4 °C | 99.31 mm |
| July | 18.3 °C | 27.9 °C | 83.82 mm |
| August | 17.4 °C | 27.2 °C | 97.79 mm |
| September | 13.8 °C | 23.6 °C | 99.06 mm |
| October | 7.7 °C | 17.3 °C | 118.62 mm |
| November | 2.6 °C | 11.5 °C | 115.32 mm |
| December | -2.1 °C | 6.4 °C | 131.83 mm |
| Annual | 6.2 °C | 15.6 °C | 1302.02 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |