Duncan, British Columbia climate data is summarized below. Average annual temperatures range from 43 °F (low) to 58.7 °F (high). Annual precipitation averages 64.5 Inches. Duncan is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -17.3 °F | -14.5 °F | 5537.2 in. |
| February | -16.8 °F | -13.2 °F | 3733.8 in. |
| March | -16.4 °F | -12.2 °F | 4343.4 in. |
| April | -15.5 °F | -10 °F | 2159 in. |
| May | -13.4 °F | -7.4 °F | 1828.8 in. |
| June | -11.9 °F | -5.8 °F | 1041.4 in. |
| July | -10.5 °F | -3.8 °F | 685.8 in. |
| August | -10.6 °F | -3.9 °F | 965.2 in. |
| September | -12.1 °F | -6.2 °F | 2362.2 in. |
| October | -14.2 °F | -9.8 °F | 5765.8 in. |
| November | -16.3 °F | -12.8 °F | 7188.2 in. |
| December | -17.5 °F | -14.7 °F | 6019.8 in. |
| Annual | 43 °F | 58.7 °F | 64.52 in. |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Moderate Drought |