Gettysburg, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 0.6 °C (low) to 13 °C (high). Annual precipitation averages 518.9 Millimeters. Gettysburg is located in USDA Plant Hardiness Zone 4b. 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 | -14.8 °C | -4.3 °C | 8.38 mm |
| February | -12.7 °C | -1.8 °C | 14.22 mm |
| March | -6.8 °C | 5.2 °C | 20.83 mm |
| April | -0.2 °C | 12.9 °C | 46.48 mm |
| May | 6.6 °C | 19.6 °C | 78.99 mm |
| June | 12.4 °C | 25.3 °C | 87.63 mm |
| July | 15.2 °C | 28.9 °C | 74.42 mm |
| August | 14.2 °C | 28.3 °C | 64.77 mm |
| September | 8.9 °C | 23.3 °C | 50.29 mm |
| October | 1.6 °C | 14.4 °C | 48.51 mm |
| November | -5.6 °C | 5.6 °C | 13.72 mm |
| December | -11.9 °C | -1.8 °C | 10.67 mm |
| Annual | 0.6 °C | 13 °C | 518.91 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |