Southington, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.9 °C (low) to 16 °C (high). Annual precipitation averages 1315.2 Millimeters. Southington 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 | -7.2 °C | 2.5 °C | 97.28 mm |
| February | -6.5 °C | 3.9 °C | 87.63 mm |
| March | -2.3 °C | 8.3 °C | 113.03 mm |
| April | 3.3 °C | 15.2 °C | 105.16 mm |
| May | 9.1 °C | 21.3 °C | 100.84 mm |
| June | 14.3 °C | 25.9 °C | 119.89 mm |
| July | 17.3 °C | 28.9 °C | 107.44 mm |
| August | 16.4 °C | 27.9 °C | 108.46 mm |
| September | 12.3 °C | 24.1 °C | 115.57 mm |
| October | 5.8 °C | 17.4 °C | 136.65 mm |
| November | 0.4 °C | 11.1 °C | 101.35 mm |
| December | -4 °C | 5.4 °C | 121.92 mm |
| Annual | 4.9 °C | 16 °C | 1315.22 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 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 |