Newbury, 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 12.8 °C (high). Annual precipitation averages 1298.2 Millimeters. Newbury is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.1 °C | -1.7 °C | 89.41 mm |
| February | -10.3 °C | 0 °C | 79.76 mm |
| March | -5.9 °C | 4.6 °C | 97.54 mm |
| April | 0.5 °C | 12.2 °C | 106.43 mm |
| May | 6.4 °C | 19 °C | 103.89 mm |
| June | 12.1 °C | 23.7 °C | 122.68 mm |
| July | 15 °C | 26.3 °C | 118.62 mm |
| August | 13.8 °C | 25.4 °C | 107.95 mm |
| September | 9.6 °C | 21.4 °C | 107.44 mm |
| October | 3.9 °C | 14.1 °C | 141.22 mm |
| November | -1.7 °C | 7.6 °C | 104.65 mm |
| December | -6.7 °C | 1.5 °C | 118.62 mm |
| Annual | 2.1 °C | 12.8 °C | 1298.21 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |