Vermillion, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 2.8 °C (low) to 15.5 °C (high). Annual precipitation averages 720.8 Millimeters. Vermillion 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 | -12.4 °C | -1.2 °C | 13.97 mm |
| February | -10.2 °C | 1.6 °C | 18.29 mm |
| March | -4.2 °C | 8.4 °C | 39.12 mm |
| April | 2.1 °C | 16.1 °C | 77.72 mm |
| May | 8.9 °C | 22.3 °C | 98.55 mm |
| June | 15.2 °C | 27.9 °C | 112.01 mm |
| July | 17.3 °C | 29.9 °C | 89.66 mm |
| August | 15.9 °C | 28.7 °C | 77.72 mm |
| September | 10.8 °C | 25.3 °C | 76.45 mm |
| October | 3.6 °C | 18 °C | 63.75 mm |
| November | -3.8 °C | 8.6 °C | 32.26 mm |
| December | -9.7 °C | 0.9 °C | 21.34 mm |
| Annual | 2.8 °C | 15.5 °C | 720.84 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 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |