Lake Cowichan, British Columbia climate data is summarized below. Average annual temperatures range from 40.1 °F (low) to 56.4 °F (high). Annual precipitation averages 71.6 Inches. 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 | -18.3 °F | -15 °F | 6019.8 in. |
| February | -17.8 °F | -13.9 °F | 4140.2 in. |
| March | -17.5 °F | -13.2 °F | 5105.4 in. |
| April | -16.2 °F | -10.8 °F | 2133.6 in. |
| May | -14.2 °F | -8.4 °F | 1727.2 in. |
| June | -13 °F | -7 °F | 965.2 in. |
| July | -11.5 °F | -4.6 °F | 863.6 in. |
| August | -11.5 °F | -4.5 °F | 1219.2 in. |
| September | -13 °F | -6.6 °F | 2844.8 in. |
| October | -15 °F | -10.1 °F | 7416.8 in. |
| November | -17 °F | -13.4 °F | 8001 in. |
| December | -18.3 °F | -15.3 °F | 5740.4 in. |
| Annual | 40.1 °F | 56.4 °F | 71.59 in. |
| 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 : 10°F to 15°F |
| Current Drought Conditions | Moderate Drought |