Horizon City, Texas has a Cold Desert Climate climate (Köppen classification: BWk). Average annual temperatures range from 10.1 °C (low) to 26 °C (high). Annual precipitation averages 232.2 Millimeters. Horizon City is located in USDA Plant Hardiness Zone 8b. 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 | -0.8 °C | 14.8 °C | 11.94 mm |
| February | 1.7 °C | 17.8 °C | 12.45 mm |
| March | 5.4 °C | 22.1 °C | 6.86 mm |
| April | 9.2 °C | 26.7 °C | 4.83 mm |
| May | 14.2 °C | 31.4 °C | 9.14 mm |
| June | 19.3 °C | 36.2 °C | 20.07 mm |
| July | 21 °C | 35.8 °C | 42.93 mm |
| August | 20.3 °C | 34.6 °C | 40.13 mm |
| September | 16.9 °C | 31.6 °C | 35.05 mm |
| October | 10.5 °C | 26.7 °C | 19.81 mm |
| November | 3.7 °C | 19.8 °C | 10.41 mm |
| December | -0.5 °C | 14.4 °C | 18.54 mm |
| Annual | 10.1 °C | 26 °C | 232.16 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 30-40 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 | BWk - Cold Desert Climate |