Blackwell, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 47.1 °F (low) to 71.2 °F (high). Annual precipitation averages 36.8 Inches. Blackwell is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 24.0 °F | 46.9 °F | 1.12 in. |
| February | 27.2 °F | 51.4 °F | 1.41 in. |
| March | 36.2 °F | 61.3 °F | 2.66 in. |
| April | 45.0 °F | 71.0 °F | 3.8 in. |
| May | 56.4 °F | 79.5 °F | 4.88 in. |
| June | 66.2 °F | 89.0 °F | 4.97 in. |
| July | 70.6 °F | 93.9 °F | 4.32 in. |
| August | 68.8 °F | 93.0 °F | 3.68 in. |
| September | 60.6 °F | 85.6 °F | 2.99 in. |
| October | 47.9 °F | 73.6 °F | 3.59 in. |
| November | 36.0 °F | 60.4 °F | 1.87 in. |
| December | 26.6 °F | 48.6 °F | 1.54 in. |
| Annual | 47.1 °F | 71.2 °F | 36.83 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |