Cullman, Alabama has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.4 °C (low) to 21.7 °C (high). Annual precipitation averages 1550.9 Millimeters. Cullman is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1 °C | 10.4 °C | 149.1 mm |
| February | 0.6 °C | 12.7 °C | 147.57 mm |
| March | 4.2 °C | 17.2 °C | 147.32 mm |
| April | 8.4 °C | 21.9 °C | 144.78 mm |
| May | 13.7 °C | 26 °C | 131.06 mm |
| June | 18.1 °C | 29.7 °C | 121.92 mm |
| July | 20.1 °C | 31.3 °C | 113.54 mm |
| August | 19.4 °C | 31.2 °C | 101.6 mm |
| September | 16 °C | 28.6 °C | 115.06 mm |
| October | 9.3 °C | 23.1 °C | 100.33 mm |
| November | 3.4 °C | 16.8 °C | 119.63 mm |
| December | 0.7 °C | 11.9 °C | 159 mm |
| Annual | 9.4 °C | 21.7 °C | 1550.91 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 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 | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |