Dellroy, Ohio has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 41.1 °F (low) to 61.5 °F (high). Annual precipitation averages 42.1 Inches. Dellroy 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.9 °F | 35.8 °F | 3.04 in. |
| February | 21.2 °F | 38.9 °F | 2.23 in. |
| March | 28.8 °F | 48.6 °F | 3.21 in. |
| April | 38.9 °F | 62.3 °F | 3.73 in. |
| May | 49.5 °F | 72.3 °F | 4.15 in. |
| June | 58.3 °F | 80.3 °F | 5.09 in. |
| July | 62.3 °F | 83.8 °F | 4.26 in. |
| August | 60.5 °F | 82.7 °F | 3.77 in. |
| September | 53.5 °F | 76.6 °F | 3.55 in. |
| October | 42.3 °F | 64.3 °F | 3.19 in. |
| November | 32.8 °F | 51.4 °F | 2.87 in. |
| December | 25.6 °F | 40.6 °F | 2.99 in. |
| Annual | 41.1 °F | 61.5 °F | 42.08 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Dfb - Humid Continental Mild Summer, Wet All Year |