O'Kean, Arkansas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 49.5 °F (low) to 69.4 °F (high). Annual precipitation averages 50.3 Inches. O'Kean is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 28.3 °F | 45.4 °F | 3.77 in. |
| February | 31.5 °F | 50.5 °F | 3.9 in. |
| March | 39.3 °F | 59.9 °F | 4.76 in. |
| April | 48.8 °F | 70.2 °F | 5.37 in. |
| May | 59.2 °F | 78.9 °F | 5.12 in. |
| June | 67.5 °F | 87.2 °F | 3.35 in. |
| July | 70.9 °F | 89.8 °F | 3.73 in. |
| August | 68.6 °F | 88.6 °F | 3.6 in. |
| September | 60.7 °F | 82.8 °F | 3.54 in. |
| October | 48.6 °F | 72.6 °F | 3.83 in. |
| November | 38.8 °F | 59.1 °F | 4.71 in. |
| December | 31.2 °F | 48.1 °F | 4.59 in. |
| Annual | 49.5 °F | 69.4 °F | 50.27 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |