Gettysburg, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 33 °F (low) to 55.3 °F (high). Annual precipitation averages 20.4 Inches. 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 | 5.4 °F | 24.2 °F | 0.33 in. |
| February | 9.1 °F | 28.8 °F | 0.56 in. |
| March | 19.7 °F | 41.3 °F | 0.82 in. |
| April | 31.7 °F | 55.2 °F | 1.83 in. |
| May | 43.8 °F | 67.3 °F | 3.11 in. |
| June | 54.3 °F | 77.6 °F | 3.45 in. |
| July | 59.3 °F | 84.0 °F | 2.93 in. |
| August | 57.6 °F | 82.9 °F | 2.55 in. |
| September | 48.0 °F | 74.0 °F | 1.98 in. |
| October | 34.9 °F | 58.0 °F | 1.91 in. |
| November | 21.9 °F | 42.0 °F | 0.54 in. |
| December | 10.5 °F | 28.7 °F | 0.42 in. |
| Annual | 33 °F | 55.3 °F | 20.43 in. |
| 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 : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |