Lilburn, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.4 °C (low) to 22.2 °C (high). Annual precipitation averages 1388.4 Millimeters. Lilburn 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 °C | 11.3 °C | 124.97 mm |
| February | 1.7 °C | 13.6 °C | 126.49 mm |
| March | 5.2 °C | 18 °C | 133.86 mm |
| April | 9.4 °C | 22.6 °C | 109.22 mm |
| May | 14.5 °C | 26.6 °C | 100.58 mm |
| June | 19 °C | 30.1 °C | 115.82 mm |
| July | 20.8 °C | 31.6 °C | 135.13 mm |
| August | 20.4 °C | 31.2 °C | 112.52 mm |
| September | 17.1 °C | 28.3 °C | 106.93 mm |
| October | 10.7 °C | 23.1 °C | 93.98 mm |
| November | 4.7 °C | 17.3 °C | 109.22 mm |
| December | 1.7 °C | 12.8 °C | 119.63 mm |
| Annual | 10.4 °C | 22.2 °C | 1388.35 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 |