Terrace Bay, Ontario climate data is summarized below. Average annual temperatures range from 29.4 °F (low) to 42.1 °F (high). Annual precipitation averages 21.9 Inches. Terrace Bay is located in USDA Plant Hardiness Zone 3b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -27.5 °F | -22.5 °F | 0 in. |
| February | -27.7 °F | -22.1 °F | 0 in. |
| March | -23.7 °F | -18.4 °F | 0 in. |
| April | -19.5 °F | -15.3 °F | 609.6 in. |
| May | -16.1 °F | -12.2 °F | 1981.2 in. |
| June | -13.7 °F | -9.9 °F | 2260.6 in. |
| July | -11.9 °F | -8.7 °F | 2438.4 in. |
| August | -10.8 °F | -7.7 °F | 1828.8 in. |
| September | -12.5 °F | -9.3 °F | 2159 in. |
| October | -15.4 °F | -12.5 °F | 1981.2 in. |
| November | -19.2 °F | -16.3 °F | 863.6 in. |
| December | -24.9 °F | -20.7 °F | 0 in. |
| Annual | 29.4 °F | 42.1 °F | 21.88 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 3b : -35°F to -30°F |
| Current Drought Conditions | Normal |