Columbia Falls, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 31.4 °F (low) to 54.9 °F (high). Annual precipitation averages 21.3 Inches. Columbia Falls is located in USDA Plant Hardiness Zone 5b. 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 | 16.8 °F | 31.3 °F | 1.79 in. |
| February | 17.7 °F | 35.7 °F | 1.29 in. |
| March | 23.8 °F | 44.3 °F | 1.42 in. |
| April | 30.2 °F | 53.9 °F | 1.82 in. |
| May | 37.9 °F | 64.4 °F | 2.27 in. |
| June | 44.3 °F | 70.6 °F | 3.46 in. |
| July | 48.1 °F | 81.4 °F | 1.31 in. |
| August | 46.2 °F | 81.4 °F | 0.97 in. |
| September | 38.9 °F | 70.2 °F | 1.36 in. |
| October | 30.4 °F | 54.5 °F | 1.86 in. |
| November | 24.4 °F | 39.7 °F | 1.73 in. |
| December | 18.3 °F | 31.1 °F | 2.03 in. |
| Annual | 31.4 °F | 54.9 °F | 21.31 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |