Porterdale, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 50.7 °F (low) to 73.7 °F (high). Annual precipitation averages 50.5 Inches. Porterdale 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 | 32.5 °F | 54.8 °F | 4.59 in. |
| February | 35.3 °F | 58.4 °F | 4.8 in. |
| March | 41.3 °F | 66.4 °F | 4.86 in. |
| April | 48.5 °F | 74.3 °F | 3.91 in. |
| May | 57.8 °F | 81.7 °F | 2.96 in. |
| June | 66.0 °F | 87.6 °F | 4.65 in. |
| July | 69.4 °F | 90.4 °F | 4.74 in. |
| August | 68.7 °F | 89.2 °F | 4.45 in. |
| September | 62.7 °F | 84.3 °F | 3.77 in. |
| October | 51.0 °F | 74.9 °F | 3.29 in. |
| November | 40.2 °F | 64.9 °F | 3.87 in. |
| December | 35.0 °F | 57.0 °F | 4.59 in. |
| Annual | 50.7 °F | 73.7 °F | 50.48 in. |
| 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 : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |