Franklin, Alabama has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.6 °C (low) to 24.5 °C (high). Annual precipitation averages 1394.5 Millimeters. Franklin is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.8 °C | 14.3 °C | 126.24 mm |
| February | 3.4 °C | 16.7 °C | 127.51 mm |
| March | 6.7 °C | 20.9 °C | 147.07 mm |
| April | 10.3 °C | 24.8 °C | 113.03 mm |
| May | 15.4 °C | 28.7 °C | 98.04 mm |
| June | 19.8 °C | 31.7 °C | 122.94 mm |
| July | 21.6 °C | 32.9 °C | 127.76 mm |
| August | 21.1 °C | 32.7 °C | 113.79 mm |
| September | 18.2 °C | 30.6 °C | 96.01 mm |
| October | 11.8 °C | 25.5 °C | 74.42 mm |
| November | 5.6 °C | 19.9 °C | 114.55 mm |
| December | 3.1 °C | 15.7 °C | 133.1 mm |
| Annual | 11.6 °C | 24.5 °C | 1394.46 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |