Fort Gibson, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 49.8 °F (low) to 71.9 °F (high). Annual precipitation averages 45.7 Inches. Fort Gibson 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 | 27.6 °F | 49.4 °F | 2.28 in. |
| February | 31.2 °F | 53.8 °F | 2.34 in. |
| March | 39.8 °F | 62.8 °F | 3.75 in. |
| April | 48.5 °F | 71.7 °F | 4.89 in. |
| May | 58.6 °F | 79.2 °F | 6.08 in. |
| June | 67.6 °F | 87.5 °F | 4.96 in. |
| July | 71.7 °F | 92.5 °F | 3.46 in. |
| August | 70.2 °F | 92.6 °F | 3.12 in. |
| September | 62.4 °F | 85.0 °F | 4.31 in. |
| October | 50.4 °F | 73.9 °F | 3.83 in. |
| November | 39.4 °F | 62.3 °F | 3.63 in. |
| December | 30.7 °F | 51.5 °F | 3.04 in. |
| Annual | 49.8 °F | 71.9 °F | 45.69 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 | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |