Bigfork, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.4 °C (low) to 12.8 °C (high). Annual precipitation averages 622.3 Millimeters. Bigfork is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.5 °C | 0 °C | 55.63 mm |
| February | -7.2 °C | 2.2 °C | 38.61 mm |
| March | -3.9 °C | 7.1 °C | 41.15 mm |
| April | -0.4 °C | 12.3 °C | 56.39 mm |
| May | 3.8 °C | 17.9 °C | 58.67 mm |
| June | 7.3 °C | 21.3 °C | 99.57 mm |
| July | 9.7 °C | 27.4 °C | 35.31 mm |
| August | 8.7 °C | 27.3 °C | 26.67 mm |
| September | 4.7 °C | 21.2 °C | 45.21 mm |
| October | 0 °C | 12.7 °C | 56.13 mm |
| November | -3.5 °C | 4.7 °C | 55.63 mm |
| December | -6.8 °C | -0.1 °C | 53.34 mm |
| Annual | 0.4 °C | 12.8 °C | 622.31 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |