Fort St. John, British Columbia climate data is summarized below. Average annual temperatures range from -2.9 °C (low) to 7.4 °C (high). Annual precipitation averages 366 Millimeters. Fort St. John is located in USDA Plant Hardiness Zone 3a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -15.12 °C | -6.63 °C | 0 mm |
| February | -14.13 °C | -5.02 °C | 0 mm |
| March | -11.51 °C | -1.19 °C | 0 mm |
| April | -2.29 °C | 7.78 °C | 26 mm |
| May | 3.52 °C | 16.23 °C | 44 mm |
| June | 8.26 °C | 20.2 °C | 93 mm |
| July | 10.6 °C | 23.23 °C | 69 mm |
| August | 9.27 °C | 22.29 °C | 49 mm |
| September | 5.03 °C | 16.91 °C | 46 mm |
| October | -0.31 °C | 7.66 °C | 39 mm |
| November | -10.8 °C | -3.37 °C | 0 mm |
| December | -17.79 °C | -9.6 °C | 0 mm |
| Annual | -2.9 °C | 7.4 °C | 366 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 3a : -40°C to -37.2°C |
| Current Drought Conditions | Normal |