Okreek, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 35.6 °F (low) to 60.4 °F (high). Annual precipitation averages 21.6 Inches. Okreek 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 Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.1 °F | 34.1 °F | 0.45 in. |
| February | 14.7 °F | 37.8 °F | 0.62 in. |
| March | 23.4 °F | 48.3 °F | 1.13 in. |
| April | 33.1 °F | 58.0 °F | 2.49 in. |
| May | 44.3 °F | 68.8 °F | 3.49 in. |
| June | 55.2 °F | 79.6 °F | 3.76 in. |
| July | 61.1 °F | 87.6 °F | 2.68 in. |
| August | 59.0 °F | 86.3 °F | 2.15 in. |
| September | 49.4 °F | 77.7 °F | 1.91 in. |
| October | 35.9 °F | 62.3 °F | 1.71 in. |
| November | 24.0 °F | 48.0 °F | 0.7 in. |
| December | 14.9 °F | 36.4 °F | 0.53 in. |
| Annual | 35.6 °F | 60.4 °F | 21.62 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |