Green Valley, South Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 35.9 °F (low) to 59.4 °F (high). Annual precipitation averages 18 Inches. Green Valley is located in USDA Plant Hardiness Zone 5a. 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 | 14.1 °F | 36.1 °F | 0.33 in. |
| February | 16.0 °F | 38.0 °F | 0.49 in. |
| March | 24.2 °F | 47.9 °F | 0.96 in. |
| April | 33.0 °F | 56.0 °F | 2.05 in. |
| May | 43.8 °F | 65.4 °F | 3.74 in. |
| June | 53.9 °F | 77.0 °F | 3.0 in. |
| July | 60.4 °F | 85.7 °F | 2.17 in. |
| August | 58.5 °F | 84.8 °F | 1.68 in. |
| September | 49.3 °F | 75.6 °F | 1.26 in. |
| October | 36.4 °F | 60.8 °F | 1.48 in. |
| November | 25.0 °F | 47.9 °F | 0.49 in. |
| December | 16.4 °F | 37.5 °F | 0.37 in. |
| Annual | 35.9 °F | 59.4 °F | 18.02 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 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 |