Terlton, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9 °C (low) to 22.3 °C (high). Annual precipitation averages 1020.8 Millimeters. Terlton 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 | -3.4 °C | 9.8 °C | 40.39 mm |
| February | -1.4 °C | 12.3 °C | 42.93 mm |
| March | 3.6 °C | 17.4 °C | 76.96 mm |
| April | 8.6 °C | 22.7 °C | 108.97 mm |
| May | 14 °C | 26.2 °C | 144.78 mm |
| June | 19 °C | 30.9 °C | 119.63 mm |
| July | 21.2 °C | 33.8 °C | 96.27 mm |
| August | 20.3 °C | 33.9 °C | 93.73 mm |
| September | 15.6 °C | 29.3 °C | 95.76 mm |
| October | 9.1 °C | 23.6 °C | 87.88 mm |
| November | 3.2 °C | 16.7 °C | 63.25 mm |
| December | -1.7 °C | 10.7 °C | 50.29 mm |
| Annual | 9 °C | 22.3 °C | 1020.84 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |