Norcross, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.2 °C (low) to 21.8 °C (high). Annual precipitation averages 1416.8 Millimeters. Norcross 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 | -0.3 °C | 10.8 °C | 128.02 mm |
| February | 1.3 °C | 13.1 °C | 129.29 mm |
| March | 4.8 °C | 17.6 °C | 136.14 mm |
| April | 9.2 °C | 22.2 °C | 110.74 mm |
| May | 14.3 °C | 26.3 °C | 102.87 mm |
| June | 18.8 °C | 29.7 °C | 120.9 mm |
| July | 20.7 °C | 31.3 °C | 139.45 mm |
| August | 20.3 °C | 30.9 °C | 113.54 mm |
| September | 16.8 °C | 28 °C | 110.24 mm |
| October | 10.4 °C | 22.7 °C | 97.03 mm |
| November | 4.3 °C | 16.9 °C | 109.98 mm |
| December | 1.4 °C | 12.3 °C | 118.62 mm |
| Annual | 10.2 °C | 21.8 °C | 1416.82 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |