Ansonia, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.4 °C (low) to 15.9 °C (high). Annual precipitation averages 1299.5 Millimeters. Ansonia is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.6 °C | 2.7 °C | 98.55 mm |
| February | -5.9 °C | 4 °C | 86.87 mm |
| March | -1.9 °C | 8.2 °C | 117.6 mm |
| April | 3.8 °C | 14.7 °C | 110.49 mm |
| May | 9.4 °C | 20.9 °C | 104.9 mm |
| June | 14.6 °C | 25.4 °C | 112.27 mm |
| July | 17.7 °C | 28.6 °C | 101.35 mm |
| August | 16.9 °C | 27.6 °C | 103.12 mm |
| September | 12.9 °C | 24 °C | 121.92 mm |
| October | 6.4 °C | 17.5 °C | 126.49 mm |
| November | 1 °C | 11.2 °C | 103.89 mm |
| December | -3.4 °C | 5.6 °C | 112.01 mm |
| Annual | 5.4 °C | 15.9 °C | 1299.46 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 |