Hamilton, Ontario climate data is summarized below. Average annual temperatures range from 4.8 °C (low) to 13.9 °C (high). Annual precipitation averages 987 Millimeters. Hamilton is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.25 °C | -0.29 °C | 33 mm |
| February | -8.6 °C | -0.69 °C | 36 mm |
| March | -2.92 °C | 5.83 °C | 89 mm |
| April | 2.63 °C | 12.81 °C | 102 mm |
| May | 8.59 °C | 19.93 °C | 103 mm |
| June | 14.27 °C | 25.09 °C | 106 mm |
| July | 16.99 °C | 27.99 °C | 111 mm |
| August | 16.48 °C | 27.01 °C | 100 mm |
| September | 12.33 °C | 22.48 °C | 76 mm |
| October | 6.81 °C | 15.49 °C | 86 mm |
| November | 1.17 °C | 8.84 °C | 70 mm |
| December | -3.44 °C | 2.58 °C | 75 mm |
| Annual | 4.8 °C | 13.9 °C | 987 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |