Cottonwood, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 33.9 °F (low) to 61.4 °F (high). Annual precipitation averages 17.8 Inches. Cottonwood 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 | 10.3 °F | 34.7 °F | 0.43 in. |
| February | 13.2 °F | 38.6 °F | 0.55 in. |
| March | 22.0 °F | 49.1 °F | 0.98 in. |
| April | 31.7 °F | 59.1 °F | 1.99 in. |
| May | 43.3 °F | 69.7 °F | 3.1 in. |
| June | 53.9 °F | 80.5 °F | 3.13 in. |
| July | 60.2 °F | 89.2 °F | 2.23 in. |
| August | 57.7 °F | 88.5 °F | 1.63 in. |
| September | 47.2 °F | 79.3 °F | 1.26 in. |
| October | 33.8 °F | 63.2 °F | 1.48 in. |
| November | 21.3 °F | 48.3 °F | 0.53 in. |
| December | 12.4 °F | 36.7 °F | 0.46 in. |
| Annual | 33.9 °F | 61.4 °F | 17.77 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 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 | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |