Sherman, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.2 °C (low) to 15.5 °C (high). Annual precipitation averages 1258.8 Millimeters. Sherman 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.3 °C | 1.8 °C | 87.38 mm |
| February | -7.2 °C | 3.4 °C | 71.63 mm |
| March | -3.2 °C | 7.9 °C | 96.77 mm |
| April | 2.8 °C | 15.1 °C | 98.55 mm |
| May | 8.5 °C | 21 °C | 96.27 mm |
| June | 13.6 °C | 25.5 °C | 116.59 mm |
| July | 16.6 °C | 28.3 °C | 119.13 mm |
| August | 15.7 °C | 27.3 °C | 124.46 mm |
| September | 11.6 °C | 23.3 °C | 118.62 mm |
| October | 5.1 °C | 16.8 °C | 125.73 mm |
| November | -0.2 °C | 10.6 °C | 97.03 mm |
| December | -4.7 °C | 4.4 °C | 106.68 mm |
| Annual | 4.2 °C | 15.5 °C | 1258.84 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 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 |