Bigfork, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.7 °F (low) to 55.1 °F (high). Annual precipitation averages 24.5 Inches. 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 | 18.5 °F | 32.0 °F | 2.19 in. |
| February | 19.1 °F | 35.9 °F | 1.52 in. |
| March | 24.9 °F | 44.8 °F | 1.62 in. |
| April | 31.3 °F | 54.1 °F | 2.22 in. |
| May | 38.9 °F | 64.2 °F | 2.31 in. |
| June | 45.2 °F | 70.3 °F | 3.92 in. |
| July | 49.4 °F | 81.4 °F | 1.39 in. |
| August | 47.7 °F | 81.1 °F | 1.05 in. |
| September | 40.5 °F | 70.1 °F | 1.78 in. |
| October | 32.0 °F | 54.8 °F | 2.21 in. |
| November | 25.7 °F | 40.4 °F | 2.19 in. |
| December | 19.7 °F | 31.9 °F | 2.1 in. |
| Annual | 32.7 °F | 55.1 °F | 24.5 in. |
| 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 : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |