Portage, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5 °C (low) to 15.6 °C (high). Annual precipitation averages 892.3 Millimeters. Portage 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 | -7.6 °C | 0.6 °C | 58.17 mm |
| February | -6.6 °C | 2.3 °C | 50.29 mm |
| March | -2.2 °C | 7.9 °C | 58.67 mm |
| April | 3.5 °C | 15.3 °C | 88.39 mm |
| May | 10 °C | 21.8 °C | 99.82 mm |
| June | 15.6 °C | 27.1 °C | 87.63 mm |
| July | 17.3 °C | 29.1 °C | 92.2 mm |
| August | 16.2 °C | 27.9 °C | 90.68 mm |
| September | 12.1 °C | 24.8 °C | 71.12 mm |
| October | 6 °C | 17.7 °C | 71.37 mm |
| November | 0.3 °C | 9.7 °C | 64.52 mm |
| December | -4.3 °C | 3.3 °C | 59.44 mm |
| Annual | 5 °C | 15.6 °C | 892.3 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 | Dfa - Humid Continental Hot Summers With Year Around Precipitation |