Irondale, Ohio has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 5.5 °C (low) to 16.6 °C (high). Annual precipitation averages 1056.1 Millimeters. Irondale 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 | -6.1 °C | 2.7 °C | 79.76 mm |
| February | -5.4 °C | 4.4 °C | 61.21 mm |
| March | -1.5 °C | 9.6 °C | 84.07 mm |
| April | 4.1 °C | 17.2 °C | 94.49 mm |
| May | 9.8 °C | 22.3 °C | 101.09 mm |
| June | 14.7 °C | 26.8 °C | 111.25 mm |
| July | 17.1 °C | 28.8 °C | 108.2 mm |
| August | 16.3 °C | 28.2 °C | 93.22 mm |
| September | 12.7 °C | 24.7 °C | 93.73 mm |
| October | 6.4 °C | 18 °C | 77.22 mm |
| November | 1 °C | 11.1 °C | 73.66 mm |
| December | -3.1 °C | 5.2 °C | 78.23 mm |
| Annual | 5.5 °C | 16.6 °C | 1056.13 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 6b : -20.6°C to -17.8°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 |