Forestdale, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 6 °C (low) to 14.7 °C (high). Annual precipitation averages 1296.9 Millimeters. Forestdale is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.4 °C | 3.6 °C | 106.93 mm |
| February | -4.9 °C | 4 °C | 95.25 mm |
| March | -1.5 °C | 7.2 °C | 132.33 mm |
| April | 3.6 °C | 12.6 °C | 118.36 mm |
| May | 8.9 °C | 17.9 °C | 92.2 mm |
| June | 14.2 °C | 22.7 °C | 98.55 mm |
| July | 18 °C | 26.1 °C | 77.98 mm |
| August | 17.4 °C | 25.4 °C | 91.69 mm |
| September | 13.8 °C | 22 °C | 108.2 mm |
| October | 7.8 °C | 16.3 °C | 125.73 mm |
| November | 2.6 °C | 11.4 °C | 111 mm |
| December | -2.1 °C | 6.6 °C | 138.68 mm |
| Annual | 6 °C | 14.7 °C | 1296.9 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Dfb - Humid Continental Mild Summer, Wet All Year |