Rapid City, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 35.9 °F (low) to 59.1 °F (high). Annual precipitation averages 20 Inches. Rapid City is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.7 °F | 36.8 °F | 0.33 in. |
| February | 16.2 °F | 38.1 °F | 0.51 in. |
| March | 24.3 °F | 47.7 °F | 0.99 in. |
| April | 32.7 °F | 55.6 °F | 2.17 in. |
| May | 43.2 °F | 64.8 °F | 4.03 in. |
| June | 53.4 °F | 76.5 °F | 3.3 in. |
| July | 60.1 °F | 84.9 °F | 2.53 in. |
| August | 58.1 °F | 84.0 °F | 2.18 in. |
| September | 48.9 °F | 74.9 °F | 1.5 in. |
| October | 36.3 °F | 60.4 °F | 1.52 in. |
| November | 25.6 °F | 47.9 °F | 0.5 in. |
| December | 16.8 °F | 38.0 °F | 0.39 in. |
| Annual | 35.9 °F | 59.1 °F | 19.95 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°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 |