Merrickville, Ontario climate data is summarized below. Average annual temperatures range from 35.3 °F (low) to 54.1 °F (high). Annual precipitation averages 19.2 Inches. Merrickville 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 | -24.9 °F | -19.8 °F | 0 in. |
| February | -24.9 °F | -19.6 °F | 0 in. |
| March | -21.4 °F | -15.7 °F | 457.2 in. |
| April | -17.1 °F | -10.9 °F | 1244.6 in. |
| May | -13.6 °F | -6.7 °F | 1447.8 in. |
| June | -10.7 °F | -4.4 °F | 1828.8 in. |
| July | -9.5 °F | -3 °F | 2336.8 in. |
| August | -10 °F | -3.4 °F | 1828.8 in. |
| September | -12.5 °F | -5.9 °F | 1270 in. |
| October | -15.4 °F | -9.9 °F | 1117.6 in. |
| November | -18.7 °F | -13.9 °F | 660.4 in. |
| December | -22.4 °F | -18.3 °F | 228.6 in. |
| Annual | 35.3 °F | 54.1 °F | 19.23 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 |