Winner, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 36.6 °F (low) to 60.5 °F (high). Annual precipitation averages 22.8 Inches. Winner is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 11.8 °F | 32.7 °F | 0.53 in. |
| February | 15.2 °F | 37.0 °F | 0.59 in. |
| March | 23.9 °F | 47.9 °F | 1.08 in. |
| April | 34.2 °F | 59.0 °F | 2.77 in. |
| May | 45.9 °F | 69.7 °F | 3.52 in. |
| June | 56.7 °F | 80.3 °F | 3.95 in. |
| July | 62.2 °F | 88.1 °F | 2.5 in. |
| August | 60.2 °F | 86.5 °F | 2.37 in. |
| September | 51.1 °F | 78.2 °F | 2.06 in. |
| October | 37.5 °F | 63.4 °F | 2.02 in. |
| November | 25.0 °F | 47.5 °F | 0.79 in. |
| December | 15.5 °F | 35.6 °F | 0.61 in. |
| Annual | 36.6 °F | 60.5 °F | 22.79 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |