Summit, South Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.2 °C (low) to 11.5 °C (high). Annual precipitation averages 648.7 Millimeters. Summit is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -16.7 °C | -6.9 °C | 16.76 mm |
| February | -14.5 °C | -4 °C | 16.76 mm |
| March | -7.9 °C | 3.1 °C | 28.19 mm |
| April | -0.9 °C | 11.9 °C | 57.15 mm |
| May | 6.1 °C | 19.3 °C | 78.74 mm |
| June | 12.1 °C | 24.5 °C | 100.08 mm |
| July | 14.5 °C | 27.3 °C | 104.9 mm |
| August | 13.6 °C | 26.6 °C | 72.14 mm |
| September | 8.9 °C | 22.3 °C | 70.36 mm |
| October | 1.6 °C | 13.9 °C | 63.75 mm |
| November | -6.2 °C | 4.1 °C | 22.61 mm |
| December | -12.9 °C | -3.8 °C | 17.27 mm |
| Annual | -0.2 °C | 11.5 °C | 648.71 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |