Bridgewater, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.2 °C (low) to 12 °C (high). Annual precipitation averages 1319.8 Millimeters. Bridgewater 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 Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.7 °C | -2.9 °C | 91.69 mm |
| February | -12.1 °C | -1.1 °C | 82.3 mm |
| March | -6.8 °C | 3.7 °C | 96.77 mm |
| April | -0.1 °C | 11.4 °C | 102.36 mm |
| May | 6.1 °C | 18.5 °C | 104.65 mm |
| June | 11.2 °C | 23.1 °C | 128.27 mm |
| July | 14 °C | 25.8 °C | 123.95 mm |
| August | 13.2 °C | 25.1 °C | 113.79 mm |
| September | 9.1 °C | 20.8 °C | 110.24 mm |
| October | 2.9 °C | 13.5 °C | 140.72 mm |
| November | -2.5 °C | 6.3 °C | 107.7 mm |
| December | -8.4 °C | 0.3 °C | 117.35 mm |
| Annual | 1.2 °C | 12 °C | 1319.79 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |