Rapid Valley, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 35.9 °F (low) to 59.3 °F (high). Annual precipitation averages 18.9 Inches. Rapid Valley is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.4 °F | 36.4 °F | 0.33 in. |
| February | 16.1 °F | 38.1 °F | 0.5 in. |
| March | 24.2 °F | 47.8 °F | 0.98 in. |
| April | 32.8 °F | 55.8 °F | 2.1 in. |
| May | 43.5 °F | 65.1 °F | 3.88 in. |
| June | 53.5 °F | 76.7 °F | 3.17 in. |
| July | 60.2 °F | 85.4 °F | 2.29 in. |
| August | 58.3 °F | 84.4 °F | 1.88 in. |
| September | 49.0 °F | 75.3 °F | 1.37 in. |
| October | 36.4 °F | 60.6 °F | 1.49 in. |
| November | 25.2 °F | 47.8 °F | 0.5 in. |
| December | 16.6 °F | 37.7 °F | 0.39 in. |
| Annual | 35.9 °F | 59.3 °F | 18.88 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| 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 |