Duncan, British Columbia climate data is summarized below. Average annual temperatures range from 6.2 °C (low) to 14.9 °C (high). Annual precipitation averages 1639 Millimeters. 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 | 0.88 °C | 5.95 °C | 218 mm |
| February | 1.75 °C | 8.21 °C | 147 mm |
| March | 2.44 °C | 10.04 °C | 171 mm |
| April | 4.15 °C | 13.95 °C | 85 mm |
| May | 7.96 °C | 18.68 °C | 72 mm |
| June | 10.59 °C | 21.58 °C | 41 mm |
| July | 13.07 °C | 25.16 °C | 27 mm |
| August | 12.97 °C | 25.07 °C | 38 mm |
| September | 10.16 °C | 20.86 °C | 93 mm |
| October | 6.42 °C | 14.44 °C | 227 mm |
| November | 2.63 °C | 8.96 °C | 283 mm |
| December | 0.56 °C | 5.46 °C | 237 mm |
| Annual | 6.2 °C | 14.9 °C | 1639 mm |
| 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 : -12.2°C to -9.4°C |
| Current Drought Conditions | Moderate Drought |