Deadwood, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -0.2 °C (low) to 13.8 °C (high). Annual precipitation averages 783.6 Millimeters. 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 | -10.4 °C | 2.6 °C | 35.05 mm |
| February | -10.3 °C | 2.8 °C | 38.35 mm |
| March | -6.2 °C | 7.7 °C | 52.83 mm |
| April | -2.1 °C | 11.6 °C | 88.65 mm |
| May | 3.3 °C | 16.7 °C | 135.13 mm |
| June | 8.6 °C | 22.8 °C | 102.87 mm |
| July | 12.2 °C | 27.5 °C | 78.99 mm |
| August | 11 °C | 27.1 °C | 59.94 mm |
| September | 6.2 °C | 22.1 °C | 45.97 mm |
| October | 0 °C | 14 °C | 77.47 mm |
| November | -5.4 °C | 7.6 °C | 32.77 mm |
| December | -9.6 °C | 2.7 °C | 35.56 mm |
| Annual | -0.2 °C | 13.8 °C | 783.58 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 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |