Clinton, Connecticut has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 6.8 °C (low) to 16.1 °C (high). Annual precipitation averages 1257.1 Millimeters. Clinton is located in USDA Plant Hardiness Zone 7a. 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 | -4.4 °C | 3.9 °C | 94.49 mm |
| February | -4 °C | 4.7 °C | 84.33 mm |
| March | -0.7 °C | 8.3 °C | 117.09 mm |
| April | 4.3 °C | 14.7 °C | 116.84 mm |
| May | 9.2 °C | 19.9 °C | 95.76 mm |
| June | 14.7 °C | 24.7 °C | 109.22 mm |
| July | 18.5 °C | 27.9 °C | 87.38 mm |
| August | 18.3 °C | 27 °C | 105.92 mm |
| September | 14.4 °C | 24.2 °C | 110.49 mm |
| October | 8.9 °C | 18.2 °C | 119.13 mm |
| November | 3.7 °C | 12.2 °C | 101.09 mm |
| December | -1.1 °C | 6.9 °C | 115.32 mm |
| Annual | 6.8 °C | 16.1 °C | 1257.06 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |