Okaton, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 35.9 °F (low) to 60 °F (high). Annual precipitation averages 20.1 Inches. Okaton 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 | 11.9 °F | 32.9 °F | 0.49 in. |
| February | 14.6 °F | 36.9 °F | 0.64 in. |
| March | 23.4 °F | 47.6 °F | 1.11 in. |
| April | 33.2 °F | 57.9 °F | 2.17 in. |
| May | 44.8 °F | 68.7 °F | 3.31 in. |
| June | 55.3 °F | 79.5 °F | 3.37 in. |
| July | 61.8 °F | 87.8 °F | 2.54 in. |
| August | 59.6 °F | 86.7 °F | 2.15 in. |
| September | 50.1 °F | 77.8 °F | 1.5 in. |
| October | 36.8 °F | 61.9 °F | 1.67 in. |
| November | 24.3 °F | 47.1 °F | 0.6 in. |
| December | 14.8 °F | 35.2 °F | 0.52 in. |
| Annual | 35.9 °F | 60 °F | 20.07 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 | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |