Trenton, Ontario climate data is summarized below. Average annual temperatures range from 3.3 °C (low) to 12.8 °C (high). Annual precipitation averages 738 Millimeters. Trenton 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.85 °C | -1.53 °C | 15 mm |
| February | -10.92 °C | -1.74 °C | 10 mm |
| March | -4.67 °C | 4.8 °C | 44 mm |
| April | 1.9 °C | 11.95 °C | 73 mm |
| May | 8.06 °C | 18.99 °C | 83 mm |
| June | 13.39 °C | 23.43 °C | 98 mm |
| July | 15.96 °C | 26.19 °C | 111 mm |
| August | 15.38 °C | 25.45 °C | 102 mm |
| September | 10.69 °C | 21.36 °C | 62 mm |
| October | 5.62 °C | 14.63 °C | 64 mm |
| November | -0.36 °C | 8.1 °C | 43 mm |
| December | -5.88 °C | 1.27 °C | 33 mm |
| Annual | 3.3 °C | 12.8 °C | 738 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 |
| Current Drought Conditions | Normal |