Fort Supply, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 44.5 °F (low) to 71.6 °F (high). Annual precipitation averages 24.3 Inches. Fort Supply is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 21.8 °F | 48.9 °F | 0.8 in. |
| February | 24.6 °F | 52.3 °F | 0.94 in. |
| March | 33.6 °F | 62.3 °F | 1.79 in. |
| April | 42.5 °F | 71.2 °F | 2.03 in. |
| May | 53.6 °F | 80.0 °F | 3.16 in. |
| June | 64.1 °F | 88.8 °F | 3.61 in. |
| July | 68.6 °F | 94.2 °F | 2.64 in. |
| August | 66.6 °F | 93.1 °F | 2.9 in. |
| September | 58.0 °F | 85.2 °F | 1.88 in. |
| October | 44.8 °F | 73.3 °F | 2.37 in. |
| November | 32.3 °F | 60.5 °F | 1.1 in. |
| December | 23.3 °F | 49.4 °F | 1.07 in. |
| Annual | 44.5 °F | 71.6 °F | 24.29 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |