McDonough, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.6 °C (low) to 23 °C (high). Annual precipitation averages 1317 Millimeters. McDonough is located in USDA Plant Hardiness Zone 8a. 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 | 0.5 °C | 12.4 °C | 121.16 mm |
| February | 2 °C | 14.4 °C | 115.57 mm |
| March | 5.5 °C | 18.9 °C | 131.06 mm |
| April | 9.5 °C | 23.5 °C | 100.58 mm |
| May | 14.7 °C | 27.8 °C | 84.07 mm |
| June | 19 °C | 30.9 °C | 118.87 mm |
| July | 20.8 °C | 32.6 °C | 125.48 mm |
| August | 20.4 °C | 31.9 °C | 112.52 mm |
| September | 17.2 °C | 29 °C | 100.58 mm |
| October | 10.8 °C | 23.6 °C | 85.6 mm |
| November | 4.8 °C | 17.9 °C | 99.82 mm |
| December | 1.9 °C | 13.6 °C | 121.67 mm |
| Annual | 10.6 °C | 23 °C | 1316.98 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 8a : -12.2°C to -9.4°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 |