Maryville, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.1 °C (low) to 20.9 °C (high). Annual precipitation averages 1376.4 Millimeters. Maryville 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 | -1.7 °C | 8.8 °C | 126.24 mm |
| February | -0.1 °C | 11.2 °C | 124.97 mm |
| March | 3.6 °C | 16.2 °C | 129.03 mm |
| April | 8.3 °C | 21.3 °C | 125.98 mm |
| May | 13.4 °C | 25.8 °C | 105.16 mm |
| June | 17.9 °C | 29.5 °C | 114.3 mm |
| July | 20.1 °C | 31.1 °C | 143 mm |
| August | 19.4 °C | 30.8 °C | 86.36 mm |
| September | 16.1 °C | 28.2 °C | 93.73 mm |
| October | 9.2 °C | 22.1 °C | 82.55 mm |
| November | 2.8 °C | 15.7 °C | 110.49 mm |
| December | 0.2 °C | 10.6 °C | 134.62 mm |
| Annual | 9.1 °C | 20.9 °C | 1376.43 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 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |