Winston, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.5 °C (low) to 17.2 °C (high). Annual precipitation averages 1008.4 Millimeters. Winston is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.6 °C | 1.7 °C | 27.43 mm |
| February | -6.6 °C | 4.7 °C | 39.12 mm |
| March | -0.7 °C | 11.4 °C | 62.74 mm |
| April | 4.4 °C | 17.6 °C | 96.01 mm |
| May | 11.1 °C | 22.9 °C | 144.78 mm |
| June | 16.6 °C | 27.9 °C | 133.86 mm |
| July | 18.9 °C | 30.6 °C | 113.54 mm |
| August | 17.8 °C | 29.7 °C | 110.74 mm |
| September | 12.8 °C | 25.6 °C | 105.16 mm |
| October | 6.3 °C | 18.9 °C | 81.79 mm |
| November | -0.1 °C | 11.3 °C | 51.82 mm |
| December | -5.7 °C | 4.2 °C | 41.4 mm |
| Annual | 5.5 °C | 17.2 °C | 1008.39 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |