Mount Forest, Ontario climate data is summarized below. Average annual temperatures range from 35.5 °F (low) to 52 °F (high). Annual precipitation averages 17.4 Inches. Mount Forest 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 | -23.6 °F | -19.8 °F | 0 in. |
| February | -24.4 °F | -20 °F | 0 in. |
| March | -21 °F | -16.2 °F | 533.4 in. |
| April | -17.6 °F | -11.8 °F | 736.6 in. |
| May | -14.1 °F | -7.8 °F | 1371.6 in. |
| June | -11.4 °F | -5.4 °F | 1828.8 in. |
| July | -10.2 °F | -4.1 °F | 2006.6 in. |
| August | -10.4 °F | -4.5 °F | 2387.6 in. |
| September | -12.5 °F | -6.7 °F | 1066.8 in. |
| October | -15.2 °F | -10.6 °F | 660.4 in. |
| November | -18.4 °F | -14.4 °F | 406.4 in. |
| December | -21.3 °F | -18.1 °F | 203.2 in. |
| Annual | 35.5 °F | 52 °F | 17.35 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |