Custer City, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.6 °C (low) to 22 °C (high). Annual precipitation averages 757.7 Millimeters. Custer City 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 Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.6 °C | 9.5 °C | 24.38 mm |
| February | -2.1 °C | 11.3 °C | 30.99 mm |
| March | 2.6 °C | 16.7 °C | 56.39 mm |
| April | 7.2 °C | 21.4 °C | 74.42 mm |
| May | 13.3 °C | 26.5 °C | 104.14 mm |
| June | 18.8 °C | 31.8 °C | 97.54 mm |
| July | 21.2 °C | 34.8 °C | 61.98 mm |
| August | 20.4 °C | 34.2 °C | 88.9 mm |
| September | 16.2 °C | 29.7 °C | 70.61 mm |
| October | 9.1 °C | 22.8 °C | 74.42 mm |
| November | 2.5 °C | 15.9 °C | 38.61 mm |
| December | -2.6 °C | 9.8 °C | 35.31 mm |
| Annual | 8.6 °C | 22 °C | 757.69 mm |
| 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |