Stafford, Connecticut has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.4 °C (low) to 14.5 °C (high). Annual precipitation averages 1245.4 Millimeters. Stafford is located in USDA Plant Hardiness Zone 6a. 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 | -8.7 °C | 1.2 °C | 87.63 mm |
| February | -8.5 °C | 2.4 °C | 76.2 mm |
| March | -4.1 °C | 6.8 °C | 102.87 mm |
| April | 1.7 °C | 13.8 °C | 104.65 mm |
| May | 7.4 °C | 19.7 °C | 91.95 mm |
| June | 12.7 °C | 24.3 °C | 114.81 mm |
| July | 15.9 °C | 27.2 °C | 102.11 mm |
| August | 14.9 °C | 26.2 °C | 113.54 mm |
| September | 10.8 °C | 22.4 °C | 116.33 mm |
| October | 4.4 °C | 15.8 °C | 128.02 mm |
| November | -0.8 °C | 9.7 °C | 95 mm |
| December | -5.1 °C | 4.2 °C | 112.27 mm |
| Annual | 3.4 °C | 14.5 °C | 1245.38 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 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |