Carthage, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.9 °C (low) to 20.2 °C (high). Annual precipitation averages 1204.5 Millimeters. Carthage is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.6 °C | 6.6 °C | 54.36 mm |
| February | -2.7 °C | 9.3 °C | 58.17 mm |
| March | 2.1 °C | 14.8 °C | 88.14 mm |
| April | 7.3 °C | 20.3 °C | 134.62 mm |
| May | 13.1 °C | 24.8 °C | 169.93 mm |
| June | 18.1 °C | 29.6 °C | 131.83 mm |
| July | 20.5 °C | 32.3 °C | 100.58 mm |
| August | 19.3 °C | 32.2 °C | 92.96 mm |
| September | 14.6 °C | 27.9 °C | 112.78 mm |
| October | 8 °C | 21.7 °C | 96.52 mm |
| November | 2.2 °C | 14.4 °C | 90.42 mm |
| December | -2.7 °C | 8.5 °C | 74.17 mm |
| Annual | 7.9 °C | 20.2 °C | 1204.48 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |