Foss, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 47.5 °F (low) to 72.7 °F (high). Annual precipitation averages 28.8 Inches. Foss 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 | 25.4 °F | 50.1 °F | 0.95 in. |
| February | 28.5 °F | 53.8 °F | 1.16 in. |
| March | 36.9 °F | 63.2 °F | 2.17 in. |
| April | 45.3 °F | 71.9 °F | 2.89 in. |
| May | 56.1 °F | 80.8 °F | 4.06 in. |
| June | 65.9 °F | 90.0 °F | 3.63 in. |
| July | 70.1 °F | 95.4 °F | 2.2 in. |
| August | 68.7 °F | 94.5 °F | 3.44 in. |
| September | 61.0 °F | 86.2 °F | 2.64 in. |
| October | 48.3 °F | 74.3 °F | 2.87 in. |
| November | 36.3 °F | 61.5 °F | 1.51 in. |
| December | 27.3 °F | 51.0 °F | 1.32 in. |
| Annual | 47.5 °F | 72.7 °F | 28.84 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| 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 | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |