Atkinson, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3 °C (low) to 14.9 °C (high). Annual precipitation averages 1202.4 Millimeters. Atkinson is located in USDA Plant Hardiness Zone 6a. 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 | -9.6 °C | 1 °C | 84.84 mm |
| February | -8.7 °C | 2.6 °C | 84.58 mm |
| March | -4.4 °C | 6.9 °C | 109.98 mm |
| April | 1.4 °C | 14.3 °C | 103.89 mm |
| May | 7.3 °C | 20.2 °C | 99.06 mm |
| June | 12.6 °C | 25.1 °C | 106.17 mm |
| July | 15.7 °C | 28.1 °C | 90.93 mm |
| August | 14.7 °C | 27.3 °C | 92.2 mm |
| September | 10.4 °C | 23.2 °C | 97.79 mm |
| October | 4 °C | 16.2 °C | 123.95 mm |
| November | -1.1 °C | 9.9 °C | 97.28 mm |
| December | -5.9 °C | 4 °C | 111.76 mm |
| Annual | 3 °C | 14.9 °C | 1202.43 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |