Cornish, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 51 °F (low) to 74.8 °F (high). Annual precipitation averages 34.2 Inches. Cornish is located in USDA Plant Hardiness Zone 8a. 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 | 29.8 °F | 53.7 °F | 1.62 in. |
| February | 33.5 °F | 57.5 °F | 1.97 in. |
| March | 41.7 °F | 66.0 °F | 2.7 in. |
| April | 49.4 °F | 73.9 °F | 3.2 in. |
| May | 59.4 °F | 81.3 °F | 4.86 in. |
| June | 68.4 °F | 89.8 °F | 3.8 in. |
| July | 71.9 °F | 95.1 °F | 2.41 in. |
| August | 71.0 °F | 95.5 °F | 2.59 in. |
| September | 63.5 °F | 87.9 °F | 3.62 in. |
| October | 51.5 °F | 76.9 °F | 3.35 in. |
| November | 40.7 °F | 65.2 °F | 2.09 in. |
| December | 31.6 °F | 55.0 °F | 1.94 in. |
| Annual | 51 °F | 74.8 °F | 34.15 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : 10°F to 15°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |