Deadwood, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 31.6 °F (low) to 56.8 °F (high). Annual precipitation averages 30.9 Inches. Deadwood is located in USDA Plant Hardiness Zone 5a. 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 | 13.3 °F | 36.6 °F | 1.38 in. |
| February | 13.4 °F | 37.1 °F | 1.51 in. |
| March | 20.9 °F | 45.9 °F | 2.08 in. |
| April | 28.3 °F | 52.9 °F | 3.49 in. |
| May | 38.0 °F | 62.1 °F | 5.32 in. |
| June | 47.4 °F | 73.0 °F | 4.05 in. |
| July | 54.0 °F | 81.5 °F | 3.11 in. |
| August | 51.8 °F | 80.7 °F | 2.36 in. |
| September | 43.2 °F | 71.7 °F | 1.81 in. |
| October | 32.0 °F | 57.2 °F | 3.05 in. |
| November | 22.2 °F | 45.7 °F | 1.29 in. |
| December | 14.8 °F | 36.8 °F | 1.4 in. |
| Annual | 31.6 °F | 56.8 °F | 30.85 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |