Hilham, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.2 °C (low) to 20.1 °C (high). Annual precipitation averages 1422.4 Millimeters. Hilham is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.8 °C | 7.6 °C | 118.11 mm |
| February | -1.3 °C | 10.1 °C | 125.48 mm |
| March | 2.4 °C | 14.9 °C | 132.84 mm |
| April | 7.2 °C | 20.8 °C | 129.03 mm |
| May | 12.9 °C | 24.9 °C | 124.97 mm |
| June | 17.2 °C | 28.7 °C | 132.08 mm |
| July | 19.3 °C | 30.4 °C | 132.59 mm |
| August | 18.4 °C | 30.3 °C | 101.09 mm |
| September | 14.9 °C | 27.3 °C | 102.87 mm |
| October | 8.2 °C | 21.6 °C | 79.5 mm |
| November | 2.7 °C | 14.8 °C | 97.79 mm |
| December | -0.8 °C | 9.6 °C | 146.05 mm |
| Annual | 8.2 °C | 20.1 °C | 1422.4 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |