Hemphill, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.5 °C (low) to 25.4 °C (high). Annual precipitation averages 1427 Millimeters. Hemphill is located in USDA Plant Hardiness Zone 9a. 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 | 2.7 °C | 15.1 °C | 140.46 mm |
| February | 4.5 °C | 17.3 °C | 111.25 mm |
| March | 8.2 °C | 21.4 °C | 132.33 mm |
| April | 11.9 °C | 25.3 °C | 130.3 mm |
| May | 16.8 °C | 29.3 °C | 111.25 mm |
| June | 20.7 °C | 32.5 °C | 124.21 mm |
| July | 21.8 °C | 34.1 °C | 92.46 mm |
| August | 21.6 °C | 34.6 °C | 98.04 mm |
| September | 18.6 °C | 31.7 °C | 94.49 mm |
| October | 12.4 °C | 26.7 °C | 127.51 mm |
| November | 7.2 °C | 20.5 °C | 129.54 mm |
| December | 3.6 °C | 16 °C | 135.13 mm |
| Annual | 12.5 °C | 25.4 °C | 1426.97 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |