Stewart, British Columbia climate data is summarized below. Average annual temperatures range from 26.6 °F (low) to 36.3 °F (high). Annual precipitation averages 55.1 Inches. Stewart is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -23.4 °F | -20.8 °F | 508 in. |
| February | -23.4 °F | -20.2 °F | 177.8 in. |
| March | -22.8 °F | -19.6 °F | 482.6 in. |
| April | -20.7 °F | -17.5 °F | 1320.8 in. |
| May | -17.9 °F | -14.4 °F | 3454.4 in. |
| June | -15.9 °F | -12.3 °F | 3835.4 in. |
| July | -14.5 °F | -11.1 °F | 4089.4 in. |
| August | -14.5 °F | -10.9 °F | 5308.6 in. |
| September | -16.3 °F | -13.4 °F | 7747 in. |
| October | -18.5 °F | -16.5 °F | 6426.2 in. |
| November | -21.8 °F | -19.6 °F | 1701.8 in. |
| December | -23.4 °F | -21 °F | 457.2 in. |
| Annual | 26.6 °F | 36.3 °F | 55.05 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |