Brookhaven, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.5 °C (low) to 22 °C (high). Annual precipitation averages 1381.3 Millimeters. Brookhaven 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 | -0.1 °C | 11.2 °C | 119.89 mm |
| February | 1.6 °C | 13.4 °C | 123.19 mm |
| March | 5.2 °C | 17.8 °C | 133.1 mm |
| April | 9.7 °C | 22.4 °C | 108.71 mm |
| May | 14.8 °C | 26.4 °C | 99.57 mm |
| June | 19.2 °C | 29.9 °C | 114.3 mm |
| July | 21.1 °C | 31.4 °C | 131.57 mm |
| August | 20.6 °C | 31 °C | 111 mm |
| September | 17.2 °C | 28.1 °C | 108.46 mm |
| October | 10.8 °C | 22.8 °C | 98.3 mm |
| November | 4.6 °C | 17.2 °C | 110.74 mm |
| December | 1.7 °C | 12.7 °C | 122.43 mm |
| Annual | 10.5 °C | 22 °C | 1381.26 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 7b : -15°C to -12.2°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |