Sherman, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.5 °C (low) to 13 °C (high). Annual precipitation averages 729.8 Millimeters. Sherman is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.4 °C | -4.3 °C | 17.02 mm |
| February | -12.1 °C | -1.7 °C | 21.59 mm |
| March | -5.6 °C | 5.2 °C | 36.58 mm |
| April | 0.8 °C | 13.4 °C | 72.9 mm |
| May | 7.9 °C | 20.1 °C | 95.25 mm |
| June | 14.4 °C | 25.8 °C | 113.03 mm |
| July | 16.3 °C | 28.1 °C | 90.68 mm |
| August | 14.7 °C | 26.8 °C | 87.63 mm |
| September | 9.7 °C | 23.1 °C | 81.79 mm |
| October | 2.4 °C | 15.3 °C | 57.4 mm |
| November | -5 °C | 6.1 °C | 31.24 mm |
| December | -11.2 °C | -1.8 °C | 24.64 mm |
| Annual | 1.5 °C | 13 °C | 729.75 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |