Blackstone, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.5 °C (low) to 15.7 °C (high). Annual precipitation averages 1284.2 Millimeters. Blackstone is located in USDA Plant Hardiness Zone 6b. 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 | -7.7 °C | 2.6 °C | 102.87 mm |
| February | -6.8 °C | 3.9 °C | 88.9 mm |
| March | -2.8 °C | 8 °C | 120.9 mm |
| April | 2.8 °C | 14.8 °C | 116.33 mm |
| May | 8.4 °C | 20.6 °C | 90.42 mm |
| June | 13.6 °C | 25.2 °C | 109.73 mm |
| July | 16.9 °C | 28.2 °C | 92.2 mm |
| August | 16.1 °C | 27.4 °C | 102.36 mm |
| September | 11.9 °C | 23.6 °C | 102.87 mm |
| October | 5.6 °C | 17.2 °C | 127.25 mm |
| November | 0.4 °C | 11.1 °C | 103.89 mm |
| December | -4.2 °C | 5.4 °C | 126.49 mm |
| Annual | 4.5 °C | 15.7 °C | 1284.21 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |