Bradford, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.1 °C (low) to 13.6 °C (high). Annual precipitation averages 1270.8 Millimeters. Bradford is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.1 °C | -0.9 °C | 88.9 mm |
| February | -11.4 °C | 0.8 °C | 78.74 mm |
| March | -6.7 °C | 5.3 °C | 98.04 mm |
| April | -0.4 °C | 12.8 °C | 103.38 mm |
| May | 5.7 °C | 19.5 °C | 101.35 mm |
| June | 10.9 °C | 24.3 °C | 117.35 mm |
| July | 13.9 °C | 27.2 °C | 111 mm |
| August | 12.7 °C | 26.3 °C | 107.7 mm |
| September | 8.4 °C | 22.3 °C | 105.66 mm |
| October | 2.2 °C | 14.9 °C | 137.92 mm |
| November | -2.6 °C | 8.2 °C | 102.62 mm |
| December | -7.8 °C | 2.1 °C | 118.11 mm |
| Annual | 1.1 °C | 13.6 °C | 1270.77 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |