Bethany, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.8 °C (low) to 22 °C (high). Annual precipitation averages 873.8 Millimeters. Bethany is located in USDA Plant Hardiness Zone 7b. 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 | -2.6 °C | 9.6 °C | 31.5 mm |
| February | -0.8 °C | 11.9 °C | 36.83 mm |
| March | 4 °C | 17 °C | 65.02 mm |
| April | 8.8 °C | 21.8 °C | 88.9 mm |
| May | 14.6 °C | 26.2 °C | 126.49 mm |
| June | 19.8 °C | 30.9 °C | 119.13 mm |
| July | 22.3 °C | 33.9 °C | 81.53 mm |
| August | 21.4 °C | 33.5 °C | 79.25 mm |
| September | 16.9 °C | 29.2 °C | 81.79 mm |
| October | 10.2 °C | 23.1 °C | 76.45 mm |
| November | 3.8 °C | 16.2 °C | 45.47 mm |
| December | -1.1 °C | 10.6 °C | 41.4 mm |
| Annual | 9.8 °C | 22 °C | 873.76 mm |
| 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |