Hermleigh, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.2 °C (low) to 24.7 °C (high). Annual precipitation averages 554 Millimeters. Hermleigh 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 | -0.9 °C | 13.6 °C | 21.84 mm |
| February | 0.8 °C | 16.1 °C | 27.43 mm |
| March | 5 °C | 20.6 °C | 38.1 mm |
| April | 9.4 °C | 25.3 °C | 39.88 mm |
| May | 14.9 °C | 29.5 °C | 73.15 mm |
| June | 19.4 °C | 33.1 °C | 75.18 mm |
| July | 21.3 °C | 34.9 °C | 44.45 mm |
| August | 20.9 °C | 34.6 °C | 55.12 mm |
| September | 17 °C | 30.4 °C | 70.36 mm |
| October | 10.9 °C | 25.2 °C | 51.05 mm |
| November | 4.3 °C | 18.8 °C | 31.75 mm |
| December | -0.1 °C | 14.1 °C | 25.65 mm |
| Annual | 10.2 °C | 24.7 °C | 553.96 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 7b : -15°C to -12.2°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |