New Haven, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.1 °C (low) to 13.4 °C (high). Annual precipitation averages 1197.3 Millimeters. New Haven is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.7 °C | -0.4 °C | 115.57 mm |
| February | -7.9 °C | 0.5 °C | 87.88 mm |
| March | -4.1 °C | 4.9 °C | 86.61 mm |
| April | 1.9 °C | 12.1 °C | 89.92 mm |
| May | 8.1 °C | 19.1 °C | 88.14 mm |
| June | 13.3 °C | 23.9 °C | 90.42 mm |
| July | 16.4 °C | 26.4 °C | 92.2 mm |
| August | 15.9 °C | 25.9 °C | 92.96 mm |
| September | 11.9 °C | 22.3 °C | 98.55 mm |
| October | 6.2 °C | 15.3 °C | 125.98 mm |
| November | 0.8 °C | 8.7 °C | 114.3 mm |
| December | -4.6 °C | 2.6 °C | 114.81 mm |
| Annual | 4.1 °C | 13.4 °C | 1197.34 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 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 | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |