Fort Frances, Ontario climate data is summarized below. Average annual temperatures range from -1.8 °C (low) to 9 °C (high). Annual precipitation averages 380 Millimeters. Fort Frances is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -19.91 °C | -9.65 °C | 0 mm |
| February | -19.23 °C | -7.13 °C | 0 mm |
| March | -9.34 °C | 2.25 °C | 3 mm |
| April | -1.65 °C | 9.39 °C | 14 mm |
| May | 4.47 °C | 16.71 °C | 50 mm |
| June | 10.4 °C | 21.83 °C | 79 mm |
| July | 13.02 °C | 24.78 °C | 86 mm |
| August | 12.03 °C | 24.07 °C | 66 mm |
| September | 7.62 °C | 19.17 °C | 50 mm |
| October | 2.08 °C | 11.29 °C | 24 mm |
| November | -5.25 °C | 2.38 °C | 8 mm |
| December | -15.78 °C | -7.71 °C | 0 mm |
| Annual | -1.8 °C | 9 °C | 380 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |