Carthage, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.4 °C (low) to 24.9 °C (high). Annual precipitation averages 1339.3 Millimeters. Carthage 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 | 2.1 °C | 14.3 °C | 116.84 mm |
| February | 4.1 °C | 16.8 °C | 106.68 mm |
| March | 7.8 °C | 20.9 °C | 127.51 mm |
| April | 11.7 °C | 24.8 °C | 125.48 mm |
| May | 16.8 °C | 28.6 °C | 115.06 mm |
| June | 20.9 °C | 32.3 °C | 118.87 mm |
| July | 22.5 °C | 34.2 °C | 84.33 mm |
| August | 22.1 °C | 34.5 °C | 85.6 mm |
| September | 18.4 °C | 31.4 °C | 93.98 mm |
| October | 12 °C | 25.9 °C | 115.57 mm |
| November | 6.7 °C | 19.6 °C | 113.28 mm |
| December | 3.2 °C | 15.1 °C | 136.14 mm |
| Annual | 12.4 °C | 24.9 °C | 1339.34 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 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |