Fergus, Ontario climate data is summarized below. Average annual temperatures range from 35.8 °F (low) to 53.1 °F (high). Annual precipitation averages 28.6 Inches. 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 | -23.7 °F | -19.6 °F | 152.4 in. |
| February | -24.4 °F | -19.7 °F | 0 in. |
| March | -21.2 °F | -15.8 °F | 863.6 in. |
| April | -17.5 °F | -11.5 °F | 1524 in. |
| May | -13.9 °F | -7.4 °F | 2413 in. |
| June | -11.2 °F | -5 °F | 2844.8 in. |
| July | -9.9 °F | -3.6 °F | 2641.6 in. |
| August | -10.2 °F | -4 °F | 3302 in. |
| September | -12.4 °F | -6.3 °F | 1752.6 in. |
| October | -15.3 °F | -10.3 °F | 1524 in. |
| November | -18.5 °F | -14.1 °F | 863.6 in. |
| December | -21.2 °F | -17.9 °F | 558.8 in. |
| Annual | 35.8 °F | 53.1 °F | 28.59 in. |
| 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 : -15°F to -10°F |
| Current Drought Conditions | Normal |