Vermillion, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37 °F (low) to 60 °F (high). Annual precipitation averages 28.4 Inches. 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 | 9.7 °F | 29.8 °F | 0.55 in. |
| February | 13.7 °F | 34.9 °F | 0.72 in. |
| March | 24.5 °F | 47.1 °F | 1.54 in. |
| April | 35.7 °F | 61.0 °F | 3.06 in. |
| May | 48.0 °F | 72.1 °F | 3.88 in. |
| June | 59.3 °F | 82.2 °F | 4.41 in. |
| July | 63.2 °F | 85.9 °F | 3.53 in. |
| August | 60.7 °F | 83.7 °F | 3.06 in. |
| September | 51.5 °F | 77.5 °F | 3.01 in. |
| October | 38.4 °F | 64.4 °F | 2.51 in. |
| November | 25.1 °F | 47.4 °F | 1.27 in. |
| December | 14.6 °F | 33.7 °F | 0.84 in. |
| Annual | 37 °F | 60 °F | 28.38 in. |
| 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 : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |