Northfield, 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 °C (high). Annual precipitation averages 1078.8 Millimeters. Northfield 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 | -7.3 °C | 0.9 °C | 76.71 mm |
| February | -6.9 °C | 2.2 °C | 59.44 mm |
| March | -2.8 °C | 7.2 °C | 84.07 mm |
| April | 3.7 °C | 14.6 °C | 98.81 mm |
| May | 9.6 °C | 21.3 °C | 105.41 mm |
| June | 14.7 °C | 25.8 °C | 105.92 mm |
| July | 16.9 °C | 28.2 °C | 104.9 mm |
| August | 15.8 °C | 27.2 °C | 96.01 mm |
| September | 12 °C | 23.5 °C | 99.06 mm |
| October | 6.3 °C | 16.6 °C | 89.92 mm |
| November | 1.2 °C | 9.6 °C | 80.01 mm |
| December | -3.7 °C | 3.4 °C | 78.49 mm |
| Annual | 5 °C | 15 °C | 1078.75 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 |