Thorntonville, Texas has a Hot Semi-Arid Climate climate (Köppen classification: BSh). Average annual temperatures range from 10.1 °C (low) to 27.1 °C (high). Annual precipitation averages 310.7 Millimeters. Thorntonville is located in USDA Plant Hardiness Zone 8a. 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 | -1.2 °C | 15.8 °C | 15.49 mm |
| February | 0.8 °C | 19.1 °C | 14.73 mm |
| March | 4.7 °C | 23.4 °C | 13.72 mm |
| April | 9.1 °C | 28.3 °C | 13.21 mm |
| May | 14.8 °C | 32.7 °C | 30.99 mm |
| June | 20.1 °C | 36.5 °C | 28.96 mm |
| July | 21.4 °C | 36.6 °C | 33.27 mm |
| August | 20.8 °C | 36.1 °C | 39.12 mm |
| September | 17 °C | 32.2 °C | 56.13 mm |
| October | 10.4 °C | 27.6 °C | 32.77 mm |
| November | 3.4 °C | 20.8 °C | 14.73 mm |
| December | -0.7 °C | 16.2 °C | 17.53 mm |
| Annual | 10.1 °C | 27.1 °C | 310.65 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 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | BSh - Hot Semi-Arid Climate |