Peterborough, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.1 °C (low) to 13.9 °C (high). Annual precipitation averages 1227.6 Millimeters. Peterborough 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.8 °C | -0.3 °C | 89.15 mm |
| February | -10.2 °C | 1.4 °C | 83.06 mm |
| March | -5.6 °C | 5.8 °C | 103.38 mm |
| April | 0.6 °C | 13.3 °C | 97.54 mm |
| May | 6.7 °C | 19.4 °C | 96.52 mm |
| June | 11.7 °C | 24.4 °C | 112.78 mm |
| July | 14.7 °C | 27.2 °C | 102.36 mm |
| August | 13.8 °C | 26.3 °C | 103.89 mm |
| September | 9.5 °C | 22.2 °C | 105.66 mm |
| October | 3.3 °C | 15.1 °C | 128.02 mm |
| November | -1.9 °C | 8.7 °C | 97.28 mm |
| December | -7.1 °C | 2.7 °C | 107.95 mm |
| Annual | 2.1 °C | 13.9 °C | 1227.59 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |