Barrington, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3 °C (low) to 14.3 °C (high). Annual precipitation averages 1200.9 Millimeters. Barrington is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.6 °C | 0.2 °C | 84.84 mm |
| February | -8.8 °C | 1.8 °C | 82.55 mm |
| March | -4.2 °C | 6.1 °C | 103.63 mm |
| April | 1.3 °C | 13.4 °C | 104.9 mm |
| May | 7.1 °C | 19.4 °C | 95.25 mm |
| June | 12.5 °C | 24.7 °C | 107.7 mm |
| July | 15.5 °C | 27.7 °C | 98.55 mm |
| August | 14.7 °C | 26.9 °C | 95.5 mm |
| September | 10.4 °C | 22.9 °C | 95.76 mm |
| October | 4.3 °C | 15.8 °C | 119.89 mm |
| November | -1 °C | 9.2 °C | 101.35 mm |
| December | -6 °C | 3.2 °C | 111 mm |
| Annual | 3 °C | 14.3 °C | 1200.92 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |