Plain City, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.9 °C (low) to 16.7 °C (high). Annual precipitation averages 1045.5 Millimeters. Plain City is located in USDA Plant Hardiness Zone 6b. 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 | -6.4 °C | 1.9 °C | 74.17 mm |
| February | -5.3 °C | 3.9 °C | 59.69 mm |
| March | -0.8 °C | 9.8 °C | 81.79 mm |
| April | 4.9 °C | 17.1 °C | 100.58 mm |
| May | 11.1 °C | 23 °C | 110.74 mm |
| June | 16.1 °C | 27.6 °C | 117.09 mm |
| July | 17.8 °C | 29.1 °C | 109.73 mm |
| August | 16.7 °C | 28.4 °C | 88.65 mm |
| September | 12.7 °C | 25.4 °C | 81.28 mm |
| October | 6.3 °C | 18.5 °C | 70.87 mm |
| November | 0.8 °C | 10.8 °C | 75.44 mm |
| December | -3.3 °C | 4.6 °C | 75.44 mm |
| Annual | 5.9 °C | 16.7 °C | 1045.47 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 |