Castlegar, British Columbia climate data is summarized below. Average annual temperatures range from 1.7 °C (low) to 15.9 °C (high). Annual precipitation averages 121 Millimeters. Castlegar is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.79 °C | 1.35 °C | 0 mm |
| February | -6.39 °C | 5 °C | 0 mm |
| March | -3.98 °C | 9.35 °C | 9 mm |
| April | 0.15 °C | 15.3 °C | 8 mm |
| May | 5.53 °C | 21.74 °C | 16 mm |
| June | 9.19 °C | 25.7 °C | 25 mm |
| July | 12.18 °C | 31.58 °C | 30 mm |
| August | 11.37 °C | 31.04 °C | 14 mm |
| September | 7.13 °C | 25.11 °C | 8 mm |
| October | 2.88 °C | 16.12 °C | 8 mm |
| November | -2.06 °C | 6.47 °C | 2 mm |
| December | -7.63 °C | 1.36 °C | 1 mm |
| Annual | 1.7 °C | 15.9 °C | 121 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |