Blackgum, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.4 °C (low) to 21.6 °C (high). Annual precipitation averages 1208.3 Millimeters. Blackgum 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 | -2.7 °C | 9.3 °C | 65.53 mm |
| February | -0.8 °C | 11.7 °C | 61.72 mm |
| March | 3.9 °C | 16.5 °C | 103.12 mm |
| April | 8.4 °C | 21.4 °C | 125.48 mm |
| May | 13.9 °C | 25.4 °C | 148.84 mm |
| June | 19.1 °C | 30 °C | 126.75 mm |
| July | 21.2 °C | 33.3 °C | 84.84 mm |
| August | 20.4 °C | 33.1 °C | 81.03 mm |
| September | 16.3 °C | 28.8 °C | 117.86 mm |
| October | 9.8 °C | 22.6 °C | 129.29 mm |
| November | 3.9 °C | 16.4 °C | 93.73 mm |
| December | -1.1 °C | 10.3 °C | 70.1 mm |
| Annual | 9.4 °C | 21.6 °C | 1208.29 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |