Johnson City, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.5 °C (low) to 20 °C (high). Annual precipitation averages 1152.4 Millimeters. Johnson City is located in USDA Plant Hardiness Zone 7b. 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 | -2.9 °C | 8.1 °C | 88.14 mm |
| February | -1.5 °C | 10.3 °C | 95.76 mm |
| March | 2.1 °C | 15.2 °C | 104.14 mm |
| April | 6.6 °C | 20.8 °C | 103.63 mm |
| May | 11.7 °C | 24.9 °C | 101.6 mm |
| June | 16.1 °C | 28.3 °C | 99.57 mm |
| July | 18.2 °C | 29.8 °C | 126.75 mm |
| August | 17.5 °C | 29.4 °C | 116.33 mm |
| September | 14.1 °C | 26.9 °C | 72.39 mm |
| October | 7.6 °C | 21.4 °C | 66.04 mm |
| November | 1.8 °C | 15.1 °C | 73.91 mm |
| December | -1.2 °C | 9.8 °C | 104.14 mm |
| Annual | 7.5 °C | 20 °C | 1152.4 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |