Warren, Ohio has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.1 °C (low) to 16 °C (high). Annual precipitation averages 1051.8 Millimeters. Warren 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 | -7.6 °C | 1.7 °C | 76.96 mm |
| February | -7.1 °C | 3.3 °C | 57.66 mm |
| March | -2.9 °C | 8.5 °C | 78.99 mm |
| April | 2.6 °C | 16.1 °C | 95.5 mm |
| May | 8.3 °C | 22.1 °C | 100.58 mm |
| June | 13.3 °C | 26.6 °C | 107.19 mm |
| July | 15.6 °C | 28.8 °C | 114.05 mm |
| August | 14.6 °C | 27.9 °C | 87.88 mm |
| September | 10.9 °C | 24.4 °C | 99.82 mm |
| October | 4.9 °C | 17.4 °C | 84.58 mm |
| November | 0.1 °C | 10.4 °C | 72.64 mm |
| December | -4.1 °C | 4.4 °C | 75.95 mm |
| Annual | 4.1 °C | 16 °C | 1051.8 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 |