Somerville, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.1 °C (low) to 22 °C (high). Annual precipitation averages 1417.8 Millimeters. Somerville is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -0.9 °C | 9.5 °C | 109.22 mm |
| February | 0.7 °C | 12.2 °C | 121.92 mm |
| March | 4.8 °C | 17.1 °C | 143.76 mm |
| April | 9.6 °C | 22.4 °C | 145.54 mm |
| May | 15.1 °C | 26.7 °C | 130.81 mm |
| June | 19.5 °C | 30.7 °C | 114.05 mm |
| July | 21.3 °C | 32.3 °C | 112.52 mm |
| August | 20.3 °C | 32.2 °C | 79.76 mm |
| September | 16.3 °C | 29.2 °C | 107.19 mm |
| October | 9.8 °C | 23.5 °C | 106.68 mm |
| November | 4.2 °C | 16.7 °C | 108.71 mm |
| December | 0.6 °C | 11.2 °C | 137.67 mm |
| Annual | 10.1 °C | 22 °C | 1417.83 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |