Hiram, Ohio has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.2 °C (low) to 14.8 °C (high). Annual precipitation averages 1102.1 Millimeters. Hiram is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.9 °C | 0.6 °C | 81.28 mm |
| February | -7.4 °C | 2.2 °C | 64.52 mm |
| March | -3.1 °C | 7.3 °C | 86.36 mm |
| April | 2.9 °C | 14.7 °C | 101.09 mm |
| May | 8.9 °C | 20.8 °C | 104.39 mm |
| June | 13.9 °C | 25.4 °C | 105.92 mm |
| July | 16 °C | 27.6 °C | 109.47 mm |
| August | 15.1 °C | 26.7 °C | 90.68 mm |
| September | 11.3 °C | 23.1 °C | 101.09 mm |
| October | 5.3 °C | 16.3 °C | 92.46 mm |
| November | 0.2 °C | 9.3 °C | 82.04 mm |
| December | -4.4 °C | 3.2 °C | 82.8 mm |
| Annual | 4.2 °C | 14.8 °C | 1102.1 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Dfb - Humid Continental Mild Summer, Wet All Year |