North Haven, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.7 °C (low) to 16.1 °C (high). Annual precipitation averages 1302.5 Millimeters. North Haven is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.4 °C | 2.8 °C | 97.03 mm |
| February | -5.7 °C | 4.1 °C | 84.84 mm |
| March | -1.5 °C | 8.3 °C | 112.78 mm |
| April | 4.1 °C | 15.1 °C | 112.01 mm |
| May | 9.6 °C | 20.9 °C | 103.12 mm |
| June | 14.8 °C | 25.8 °C | 116.84 mm |
| July | 18.1 °C | 29 °C | 102.36 mm |
| August | 17.2 °C | 28 °C | 105.41 mm |
| September | 13.2 °C | 24.5 °C | 115.32 mm |
| October | 6.6 °C | 17.9 °C | 133.86 mm |
| November | 1.2 °C | 11.3 °C | 100.33 mm |
| December | -3.2 °C | 5.8 °C | 118.62 mm |
| Annual | 5.7 °C | 16.1 °C | 1302.52 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |