Custar, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.9 °C (low) to 15.7 °C (high). Annual precipitation averages 906 Millimeters. Custar 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.7 °C | 0.5 °C | 59.69 mm |
| February | -6.7 °C | 2.2 °C | 52.07 mm |
| March | -2.3 °C | 8 °C | 62.48 mm |
| April | 3.4 °C | 15.6 °C | 87.12 mm |
| May | 10 °C | 22 °C | 101.35 mm |
| June | 15.5 °C | 27.3 °C | 93.47 mm |
| July | 17.2 °C | 29.2 °C | 93.98 mm |
| August | 16.1 °C | 28 °C | 87.12 mm |
| September | 11.9 °C | 24.9 °C | 71.37 mm |
| October | 5.8 °C | 17.8 °C | 69.09 mm |
| November | 0.3 °C | 9.7 °C | 67.31 mm |
| December | -4.4 °C | 3.3 °C | 60.96 mm |
| Annual | 4.9 °C | 15.7 °C | 906.01 mm |
| 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 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 |