Lake Cowichan, British Columbia climate data is summarized below. Average annual temperatures range from 4.5 °C (low) to 13.6 °C (high). Annual precipitation averages 1818 Millimeters. Lake Cowichan is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -0.85 °C | 5.05 °C | 237 mm |
| February | -0.04 °C | 7.04 °C | 163 mm |
| March | 0.44 °C | 8.26 °C | 201 mm |
| April | 2.81 °C | 12.48 °C | 84 mm |
| May | 6.39 °C | 16.89 °C | 68 mm |
| June | 8.58 °C | 19.37 °C | 38 mm |
| July | 11.36 °C | 23.67 °C | 34 mm |
| August | 11.3 °C | 23.9 °C | 48 mm |
| September | 8.62 °C | 20.07 °C | 112 mm |
| October | 4.97 °C | 13.84 °C | 292 mm |
| November | 1.36 °C | 7.91 °C | 315 mm |
| December | -0.95 °C | 4.45 °C | 226 mm |
| Annual | 4.5 °C | 13.6 °C | 1818 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Moderate Drought |