Okmulgee, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 48.6 °F (low) to 72.1 °F (high). Annual precipitation averages 43.2 Inches. Okmulgee is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 26.7 °F | 49.9 °F | 1.94 in. |
| February | 30.0 °F | 54.0 °F | 2.11 in. |
| March | 39.0 °F | 63.0 °F | 3.2 in. |
| April | 47.3 °F | 71.8 °F | 4.43 in. |
| May | 57.6 °F | 78.9 °F | 5.81 in. |
| June | 66.9 °F | 87.5 °F | 4.68 in. |
| July | 70.2 °F | 92.8 °F | 4.24 in. |
| August | 68.9 °F | 92.9 °F | 3.22 in. |
| September | 60.5 °F | 85.4 °F | 3.91 in. |
| October | 48.5 °F | 74.5 °F | 3.98 in. |
| November | 38.1 °F | 62.6 °F | 3.12 in. |
| December | 29.4 °F | 51.8 °F | 2.53 in. |
| Annual | 48.6 °F | 72.1 °F | 43.17 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 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 | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |