Hanover, Massachusetts has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.3 °C (low) to 15.8 °C (high). Annual precipitation averages 1303.8 Millimeters. Hanover 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 | -6.6 °C | 3.1 °C | 110.24 mm |
| February | -6 °C | 4.3 °C | 98.81 mm |
| March | -1.9 °C | 8 °C | 138.68 mm |
| April | 3.5 °C | 14.3 °C | 118.11 mm |
| May | 8.8 °C | 20.1 °C | 91.69 mm |
| June | 14.1 °C | 25.2 °C | 96.01 mm |
| July | 17.5 °C | 28.3 °C | 86.36 mm |
| August | 16.7 °C | 27.7 °C | 91.95 mm |
| September | 12.7 °C | 23.7 °C | 96.52 mm |
| October | 6.6 °C | 17.3 °C | 129.29 mm |
| November | 1.3 °C | 11.5 °C | 115.32 mm |
| December | -3.4 °C | 6.2 °C | 130.81 mm |
| Annual | 5.3 °C | 15.8 °C | 1303.79 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 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 |