Clarksville, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.2 °C (low) to 23.8 °C (high). Annual precipitation averages 1248.4 Millimeters. Clarksville is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.2 °C | 12.4 °C | 84.58 mm |
| February | 2.2 °C | 14.8 °C | 95.25 mm |
| March | 6.2 °C | 19.2 °C | 122.68 mm |
| April | 10.3 °C | 23.3 °C | 115.57 mm |
| May | 15.8 °C | 27.3 °C | 136.65 mm |
| June | 20.3 °C | 31.7 °C | 97.79 mm |
| July | 22 °C | 34.1 °C | 75.18 mm |
| August | 21.4 °C | 34.4 °C | 70.1 mm |
| September | 17.8 °C | 30.9 °C | 99.57 mm |
| October | 11.1 °C | 25.1 °C | 124.71 mm |
| November | 5.6 °C | 18.7 °C | 108.46 mm |
| December | 1.4 °C | 13.6 °C | 117.86 mm |
| Annual | 11.2 °C | 23.8 °C | 1248.4 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 40-50 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 | Cfa - Humid Subtropical Climate |