Circleville, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.3 °F (low) to 63.3 °F (high). Annual precipitation averages 41.1 Inches. Circleville 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 | 22.0 °F | 37.8 °F | 2.93 in. |
| February | 23.6 °F | 41.0 °F | 2.55 in. |
| March | 31.3 °F | 51.1 °F | 3.4 in. |
| April | 41.6 °F | 64.2 °F | 4.01 in. |
| May | 52.6 °F | 73.9 °F | 4.43 in. |
| June | 61.3 °F | 82.2 °F | 4.57 in. |
| July | 64.6 °F | 84.8 °F | 4.0 in. |
| August | 62.3 °F | 84.0 °F | 3.39 in. |
| September | 55.0 °F | 78.5 °F | 2.99 in. |
| October | 43.8 °F | 66.4 °F | 2.94 in. |
| November | 33.7 °F | 53.1 °F | 2.88 in. |
| December | 27.2 °F | 42.4 °F | 2.97 in. |
| Annual | 43.3 °F | 63.3 °F | 41.06 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 |