Delta, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.5 °C (low) to 15.4 °C (high). Annual precipitation averages 911.6 Millimeters. Delta is located in USDA Plant Hardiness Zone 6a. 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 | -7.9 °C | 0.2 °C | 59.18 mm |
| February | -7.2 °C | 1.9 °C | 51.56 mm |
| March | -2.7 °C | 7.6 °C | 62.74 mm |
| April | 3.1 °C | 15.2 °C | 85.6 mm |
| May | 9.6 °C | 21.6 °C | 101.85 mm |
| June | 15.1 °C | 26.9 °C | 94.23 mm |
| July | 16.8 °C | 28.9 °C | 88.9 mm |
| August | 15.7 °C | 27.8 °C | 90.17 mm |
| September | 11.4 °C | 24.6 °C | 76.96 mm |
| October | 5.3 °C | 17.3 °C | 70.1 mm |
| November | -0.1 °C | 9.4 °C | 70.61 mm |
| December | -4.7 °C | 2.9 °C | 59.69 mm |
| Annual | 4.5 °C | 15.4 °C | 911.59 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |