Fergus, Ontario climate data is summarized below. Average annual temperatures range from 2.1 °C (low) to 11.7 °C (high). Annual precipitation averages 726 Millimeters. Fergus is located in USDA Plant Hardiness Zone 5b. 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 | -10.61 °C | -3.23 °C | 6 mm |
| February | -11.93 °C | -3.54 °C | 0 mm |
| March | -6.12 °C | 3.49 °C | 34 mm |
| April | 0.55 °C | 11.24 °C | 60 mm |
| May | 7.07 °C | 18.62 °C | 95 mm |
| June | 11.93 °C | 23.07 °C | 112 mm |
| July | 14.18 °C | 25.53 °C | 104 mm |
| August | 13.59 °C | 24.86 °C | 130 mm |
| September | 9.65 °C | 20.73 °C | 69 mm |
| October | 4.46 °C | 13.5 °C | 60 mm |
| November | -1.22 °C | 6.59 °C | 34 mm |
| December | -6.21 °C | -0.26 °C | 22 mm |
| Annual | 2.1 °C | 11.7 °C | 726 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 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |