Hamilton, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.6 °C (low) to 18.4 °C (high). Annual precipitation averages 1069.8 Millimeters. Hamilton is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.2 °C | 4.2 °C | 80.26 mm |
| February | -4 °C | 6.5 °C | 63.75 mm |
| March | 0.2 °C | 11.9 °C | 93.22 mm |
| April | 5.8 °C | 18.9 °C | 112.27 mm |
| May | 11.7 °C | 24.2 °C | 114.55 mm |
| June | 16.7 °C | 28.6 °C | 113.03 mm |
| July | 18.5 °C | 30.4 °C | 98.3 mm |
| August | 17.6 °C | 30.1 °C | 78.99 mm |
| September | 13 °C | 26.8 °C | 73.91 mm |
| October | 6.6 °C | 20.2 °C | 80.77 mm |
| November | 0.8 °C | 12.7 °C | 77.98 mm |
| December | -2.4 °C | 6.6 °C | 82.8 mm |
| Annual | 6.6 °C | 18.4 °C | 1069.83 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 |