Plain City, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.6 °F (low) to 62 °F (high). Annual precipitation averages 41.2 Inches. 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 | 20.5 °F | 35.5 °F | 2.92 in. |
| February | 22.4 °F | 39.1 °F | 2.35 in. |
| March | 30.5 °F | 49.7 °F | 3.22 in. |
| April | 40.9 °F | 62.8 °F | 3.96 in. |
| May | 51.9 °F | 73.4 °F | 4.36 in. |
| June | 60.9 °F | 81.6 °F | 4.61 in. |
| July | 64.1 °F | 84.3 °F | 4.32 in. |
| August | 62.0 °F | 83.2 °F | 3.49 in. |
| September | 54.8 °F | 77.8 °F | 3.2 in. |
| October | 43.4 °F | 65.3 °F | 2.79 in. |
| November | 33.4 °F | 51.5 °F | 2.97 in. |
| December | 26.1 °F | 40.2 °F | 2.97 in. |
| Annual | 42.6 °F | 62 °F | 41.16 in. |
| 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 : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |