Grenville, Quebec climate data is summarized below. Average annual temperatures range from 1.3 °C (low) to 11.7 °C (high). Annual precipitation averages 491 Millimeters. Grenville is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.76 °C | -5.14 °C | 0 mm |
| February | -14.39 °C | -4.35 °C | 0 mm |
| March | -7.95 °C | 2.18 °C | 13 mm |
| April | 0.75 °C | 11.75 °C | 39 mm |
| May | 7.52 °C | 19.76 °C | 48 mm |
| June | 12.8 °C | 24.3 °C | 81 mm |
| July | 15.17 °C | 26.85 °C | 105 mm |
| August | 14.33 °C | 25.86 °C | 84 mm |
| September | 9.57 °C | 21.38 °C | 51 mm |
| October | 4.08 °C | 13.77 °C | 47 mm |
| November | -2.17 °C | 6.34 °C | 20 mm |
| December | -9.84 °C | -2.04 °C | 3 mm |
| Annual | 1.3 °C | 11.7 °C | 491 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |