Merrickville, Ontario climate data is summarized below. Average annual temperatures range from 1.8 °C (low) to 12.3 °C (high). Annual precipitation averages 489 Millimeters. 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 | -12.79 °C | -3.72 °C | 0 mm |
| February | -12.87 °C | -3.19 °C | 0 mm |
| March | -6.57 °C | 3.77 °C | 18 mm |
| April | 1.18 °C | 12.39 °C | 49 mm |
| May | 7.57 °C | 19.98 °C | 57 mm |
| June | 12.71 °C | 24.07 °C | 72 mm |
| July | 14.98 °C | 26.65 °C | 92 mm |
| August | 14.07 °C | 25.81 °C | 72 mm |
| September | 9.43 °C | 21.45 °C | 50 mm |
| October | 4.21 °C | 14.13 °C | 44 mm |
| November | -1.67 °C | 7.01 °C | 26 mm |
| December | -8.32 °C | -0.99 °C | 9 mm |
| Annual | 1.8 °C | 12.3 °C | 489 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 |