Stephenville, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.6 °C (low) to 24.5 °C (high). Annual precipitation averages 859.8 Millimeters. Stephenville is located in USDA Plant Hardiness Zone 8b. 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 | 0.6 °C | 13.9 °C | 48.77 mm |
| February | 2.6 °C | 16.1 °C | 57.91 mm |
| March | 6.7 °C | 20.1 °C | 74.42 mm |
| April | 10.9 °C | 24.4 °C | 71.37 mm |
| May | 16.1 °C | 28.2 °C | 116.08 mm |
| June | 20.2 °C | 32.1 °C | 91.44 mm |
| July | 22.2 °C | 34.5 °C | 46.99 mm |
| August | 21.8 °C | 34.8 °C | 67.56 mm |
| September | 17.9 °C | 30.8 °C | 85.34 mm |
| October | 11.9 °C | 25.6 °C | 90.68 mm |
| November | 6.1 °C | 19.2 °C | 57.15 mm |
| December | 1.7 °C | 14.7 °C | 52.07 mm |
| Annual | 11.6 °C | 24.5 °C | 859.78 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |