Ashland, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.7 °C (low) to 13.5 °C (high). Annual precipitation averages 1234.7 Millimeters. Ashland is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.8 °C | -1.3 °C | 82.04 mm |
| February | -11.3 °C | 0.4 °C | 74.68 mm |
| March | -6.2 °C | 5.2 °C | 91.44 mm |
| April | 0.3 °C | 12.7 °C | 98.55 mm |
| May | 6.5 °C | 19.7 °C | 100.33 mm |
| June | 11.7 °C | 24.4 °C | 113.28 mm |
| July | 14.6 °C | 27.3 °C | 120.4 mm |
| August | 13.6 °C | 26.4 °C | 103.63 mm |
| September | 9.4 °C | 22.3 °C | 100.58 mm |
| October | 3.3 °C | 14.7 °C | 136.91 mm |
| November | -1.8 °C | 7.8 °C | 102.36 mm |
| December | -7.4 °C | 1.8 °C | 110.49 mm |
| Annual | 1.7 °C | 13.5 °C | 1234.69 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |