Tornillo, Texas has a Cold Desert Climate climate (Köppen classification: BWk). Average annual temperatures range from 9.2 °C (low) to 26.5 °C (high). Annual precipitation averages 198.9 Millimeters. Tornillo is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1.6 °C | 15.7 °C | 9.91 mm |
| February | 0.8 °C | 18.8 °C | 9.4 mm |
| March | 4.6 °C | 23.1 °C | 5.59 mm |
| April | 8.5 °C | 27.4 °C | 4.83 mm |
| May | 13.2 °C | 31.8 °C | 12.45 mm |
| June | 18.4 °C | 36.1 °C | 17.53 mm |
| July | 20.5 °C | 35.4 °C | 35.05 mm |
| August | 19.7 °C | 34.5 °C | 32.51 mm |
| September | 16.3 °C | 31.6 °C | 26.42 mm |
| October | 9.4 °C | 27.2 °C | 20.32 mm |
| November | 2.5 °C | 20.7 °C | 9.4 mm |
| December | -1.5 °C | 15.4 °C | 15.49 mm |
| Annual | 9.2 °C | 26.5 °C | 198.9 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 40-50 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 | BWk - Cold Desert Climate |