Great Barrington, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.5 °C (low) to 14.8 °C (high). Annual precipitation averages 1117.3 Millimeters. Great Barrington 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 | -10.2 °C | 0.6 °C | 74.93 mm |
| February | -9.4 °C | 2.4 °C | 56.13 mm |
| March | -4.7 °C | 6.9 °C | 73.41 mm |
| April | 1.1 °C | 14.8 °C | 96.52 mm |
| May | 7.1 °C | 21.2 °C | 88.14 mm |
| June | 12.1 °C | 25.3 °C | 113.28 mm |
| July | 14.9 °C | 27.9 °C | 118.36 mm |
| August | 14.1 °C | 26.8 °C | 112.78 mm |
| September | 9.6 °C | 22.8 °C | 104.65 mm |
| October | 3.4 °C | 16.1 °C | 105.92 mm |
| November | -1.4 °C | 9.6 °C | 81.53 mm |
| December | -6.2 °C | 3.3 °C | 91.69 mm |
| Annual | 2.5 °C | 14.8 °C | 1117.34 mm |
| 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 : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |