Iron City, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.5 °C (low) to 22 °C (high). Annual precipitation averages 1581.9 Millimeters. Iron City is located in USDA Plant Hardiness Zone 7b. 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 | -1.2 °C | 10.1 °C | 134.11 mm |
| February | 0.5 °C | 12.6 °C | 145.54 mm |
| March | 4.3 °C | 17.3 °C | 158.24 mm |
| April | 8.9 °C | 22.6 °C | 145.54 mm |
| May | 13.9 °C | 26.5 °C | 129.79 mm |
| June | 18.4 °C | 30.3 °C | 113.79 mm |
| July | 20.4 °C | 31.9 °C | 131.83 mm |
| August | 19.7 °C | 31.7 °C | 121.67 mm |
| September | 16.1 °C | 29.1 °C | 114.05 mm |
| October | 9.3 °C | 23.4 °C | 122.17 mm |
| November | 3.3 °C | 16.7 °C | 108.2 mm |
| December | 0.4 °C | 11.6 °C | 156.97 mm |
| Annual | 9.5 °C | 22 °C | 1581.9 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |