Barnesville, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11 °C (low) to 23.3 °C (high). Annual precipitation averages 1275.8 Millimeters. Barnesville is located in USDA Plant Hardiness Zone 8b. 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 | 1.1 °C | 13.1 °C | 116.08 mm |
| February | 2.6 °C | 15.2 °C | 114.55 mm |
| March | 6 °C | 19.5 °C | 128.02 mm |
| April | 9.9 °C | 23.6 °C | 102.36 mm |
| May | 14.9 °C | 27.7 °C | 79.76 mm |
| June | 19.1 °C | 30.7 °C | 109.47 mm |
| July | 20.9 °C | 32.2 °C | 127.51 mm |
| August | 20.6 °C | 31.6 °C | 106.68 mm |
| September | 17.3 °C | 29 °C | 94.23 mm |
| October | 11.2 °C | 24 °C | 79.76 mm |
| November | 5.4 °C | 18.7 °C | 96.01 mm |
| December | 2.4 °C | 14.3 °C | 121.41 mm |
| Annual | 11 °C | 23.3 °C | 1275.84 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 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |