Greenville, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.3 °C (low) to 13.8 °C (high). Annual precipitation averages 1312.7 Millimeters. Greenville is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.3 °C | -0.3 °C | 96.01 mm |
| February | -9.6 °C | 1.4 °C | 88.65 mm |
| March | -5.3 °C | 5.7 °C | 113.79 mm |
| April | 0.8 °C | 13.1 °C | 109.98 mm |
| May | 6.7 °C | 19.3 °C | 102.62 mm |
| June | 11.9 °C | 24.2 °C | 114.05 mm |
| July | 14.9 °C | 27 °C | 110.24 mm |
| August | 13.9 °C | 26.1 °C | 103.12 mm |
| September | 9.8 °C | 22.2 °C | 108.46 mm |
| October | 3.6 °C | 15 °C | 136.65 mm |
| November | -1.6 °C | 8.7 °C | 109.22 mm |
| December | -6.7 °C | 2.7 °C | 119.89 mm |
| Annual | 2.3 °C | 13.8 °C | 1312.68 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| 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 |