New Britain, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5 °C (low) to 16 °C (high). Annual precipitation averages 1312.2 Millimeters. New Britain is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.1 °C | 2.4 °C | 98.55 mm |
| February | -6.4 °C | 3.9 °C | 87.38 mm |
| March | -2.2 °C | 8.3 °C | 105.66 mm |
| April | 3.4 °C | 15.2 °C | 105.16 mm |
| May | 9.2 °C | 21.2 °C | 98.04 mm |
| June | 14.4 °C | 25.9 °C | 124.71 mm |
| July | 17.4 °C | 29 °C | 105.66 mm |
| August | 16.5 °C | 28 °C | 110.49 mm |
| September | 12.4 °C | 24 °C | 117.09 mm |
| October | 6 °C | 17.3 °C | 138.18 mm |
| November | 0.6 °C | 11 °C | 100.84 mm |
| December | -3.8 °C | 5.3 °C | 120.4 mm |
| Annual | 5 °C | 16 °C | 1312.16 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |