Somerville, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.1 °C (low) to 17.4 °C (high). Annual precipitation averages 1083.1 Millimeters. Somerville is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.1 °C | 3 °C | 81.03 mm |
| February | -4.8 °C | 5.2 °C | 64.01 mm |
| March | -0.3 °C | 10.9 °C | 92.2 mm |
| April | 5.3 °C | 17.9 °C | 113.54 mm |
| May | 11.3 °C | 23.2 °C | 119.13 mm |
| June | 16.2 °C | 27.8 °C | 117.09 mm |
| July | 18 °C | 29.6 °C | 98.81 mm |
| August | 17 °C | 29.2 °C | 76.71 mm |
| September | 12.7 °C | 25.9 °C | 75.69 mm |
| October | 6.3 °C | 19.4 °C | 80.52 mm |
| November | 0.8 °C | 11.8 °C | 79.76 mm |
| December | -3.1 °C | 5.3 °C | 84.58 mm |
| Annual | 6.1 °C | 17.4 °C | 1083.07 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |