Iron Bridge, Ontario climate data is summarized below. Average annual temperatures range from 0.4 °C (low) to 10 °C (high). Annual precipitation averages 432 Millimeters. Iron Bridge is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.81 °C | -5.4 °C | 0 mm |
| February | -15.86 °C | -4.93 °C | 0 mm |
| March | -9.38 °C | 1.4 °C | 5 mm |
| April | -1.44 °C | 8.28 °C | 19 mm |
| May | 5.71 °C | 16.35 °C | 46 mm |
| June | 11.21 °C | 21.64 °C | 75 mm |
| July | 13.88 °C | 24.08 °C | 76 mm |
| August | 13.73 °C | 23.7 °C | 78 mm |
| September | 9.18 °C | 19.16 °C | 64 mm |
| October | 3.91 °C | 12.26 °C | 41 mm |
| November | -1.57 °C | 5.4 °C | 18 mm |
| December | -9.9 °C | -2.23 °C | 10 mm |
| Annual | 0.4 °C | 10 °C | 432 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |