New Fairfield, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.4 °C (low) to 14.8 °C (high). Annual precipitation averages 1296.7 Millimeters. New Fairfield is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.1 °C | 1.3 °C | 95.5 mm |
| February | -7.1 °C | 3.1 °C | 74.42 mm |
| March | -3.1 °C | 7.6 °C | 102.87 mm |
| April | 2.9 °C | 14.6 °C | 100.08 mm |
| May | 8.7 °C | 20.2 °C | 96.01 mm |
| June | 13.8 °C | 24.6 °C | 117.35 mm |
| July | 16.7 °C | 27.4 °C | 123.44 mm |
| August | 15.9 °C | 26.3 °C | 127.51 mm |
| September | 12 °C | 22.4 °C | 121.67 mm |
| October | 5.7 °C | 16.1 °C | 123.95 mm |
| November | 0.3 °C | 10.1 °C | 103.38 mm |
| December | -4.5 °C | 4 °C | 110.49 mm |
| Annual | 4.4 °C | 14.8 °C | 1296.67 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |