Plainville, 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 1330.7 Millimeters. Plainville 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.3 °C | 2.3 °C | 98.55 mm |
| February | -6.6 °C | 3.8 °C | 88.39 mm |
| March | -2.4 °C | 8.2 °C | 107.95 mm |
| April | 3.3 °C | 15.3 °C | 105.66 mm |
| May | 9.1 °C | 21.3 °C | 97.28 mm |
| June | 14.3 °C | 26 °C | 123.7 mm |
| July | 17.3 °C | 29.1 °C | 106.68 mm |
| August | 16.3 °C | 28.1 °C | 113.79 mm |
| September | 12.2 °C | 24.1 °C | 119.38 mm |
| October | 5.8 °C | 17.4 °C | 141.99 mm |
| November | 0.4 °C | 11 °C | 103.63 mm |
| December | -4 °C | 5.3 °C | 123.7 mm |
| Annual | 4.9 °C | 16 °C | 1330.7 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |