Wessington, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.1 °C (low) to 13.8 °C (high). Annual precipitation averages 593.4 Millimeters. Wessington is located in USDA Plant Hardiness Zone 4b. 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 | -14.8 °C | -3.8 °C | 14.48 mm |
| February | -12.6 °C | -0.8 °C | 16.26 mm |
| March | -6.2 °C | 5.9 °C | 26.92 mm |
| April | 0.3 °C | 13.8 °C | 64.01 mm |
| May | 7.4 °C | 20.6 °C | 86.61 mm |
| June | 13.5 °C | 26.1 °C | 99.57 mm |
| July | 16.2 °C | 29.6 °C | 74.68 mm |
| August | 14.8 °C | 28.6 °C | 66.04 mm |
| September | 9.6 °C | 24 °C | 55.88 mm |
| October | 1.9 °C | 15.5 °C | 52.83 mm |
| November | -5.5 °C | 6.6 °C | 19.56 mm |
| December | -11.7 °C | -1.1 °C | 16.51 mm |
| Annual | 1.1 °C | 13.8 °C | 593.35 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |