Ridgefield, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.8 °C (low) to 15.1 °C (high). Annual precipitation averages 1332.2 Millimeters. Ridgefield 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 | -7.5 °C | 1.7 °C | 105.41 mm |
| February | -6.6 °C | 3.5 °C | 78.23 mm |
| March | -2.6 °C | 7.9 °C | 109.22 mm |
| April | 3.4 °C | 14.7 °C | 103.89 mm |
| May | 8.9 °C | 20.4 °C | 98.81 mm |
| June | 14.1 °C | 24.9 °C | 118.87 mm |
| July | 17.1 °C | 27.7 °C | 110.74 mm |
| August | 16.3 °C | 26.7 °C | 124.97 mm |
| September | 12.3 °C | 22.8 °C | 127 mm |
| October | 5.9 °C | 16.4 °C | 127.51 mm |
| November | 0.7 °C | 10.3 °C | 108.71 mm |
| December | -4 °C | 4.4 °C | 118.87 mm |
| Annual | 4.8 °C | 15.1 °C | 1332.23 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 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 |