Orford, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.5 °C (low) to 10.1 °C (high). Annual precipitation averages 1213.6 Millimeters. Orford is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -13.3 °C | -4.5 °C | 76.2 mm |
| February | -12.3 °C | -2.7 °C | 64.01 mm |
| March | -8.1 °C | 2.2 °C | 78.99 mm |
| April | -1.4 °C | 9.2 °C | 97.28 mm |
| May | 5.2 °C | 16.7 °C | 106.93 mm |
| June | 10.6 °C | 21.1 °C | 120.9 mm |
| July | 13.3 °C | 23.6 °C | 118.11 mm |
| August | 12.9 °C | 22.7 °C | 117.35 mm |
| September | 8.7 °C | 18.6 °C | 106.43 mm |
| October | 2.5 °C | 11.5 °C | 133.1 mm |
| November | -3.2 °C | 4.1 °C | 93.47 mm |
| December | -9.3 °C | -1.6 °C | 100.84 mm |
| Annual | 0.5 °C | 10.1 °C | 1213.61 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |