Loudon, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.7 °C (low) to 21.2 °C (high). Annual precipitation averages 1423.2 Millimeters. Loudon is located in USDA Plant Hardiness Zone 7b. 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 | -2.1 °C | 9 °C | 130.3 mm |
| February | -0.5 °C | 11.5 °C | 126.49 mm |
| March | 3.1 °C | 16.4 °C | 135.64 mm |
| April | 7.6 °C | 21.7 °C | 123.7 mm |
| May | 13 °C | 26.1 °C | 104.14 mm |
| June | 17.7 °C | 29.7 °C | 109.47 mm |
| July | 19.8 °C | 31.3 °C | 134.87 mm |
| August | 19.2 °C | 31.1 °C | 90.17 mm |
| September | 15.6 °C | 28.6 °C | 119.63 mm |
| October | 8.7 °C | 22.5 °C | 92.2 mm |
| November | 2.6 °C | 15.8 °C | 111.76 mm |
| December | -0.3 °C | 10.7 °C | 144.78 mm |
| Annual | 8.7 °C | 21.2 °C | 1423.15 mm |
| 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |