Kettle Falls, Washington has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.2 °C (low) to 15.1 °C (high). Annual precipitation averages 496.1 Millimeters. Kettle Falls is located in USDA Plant Hardiness Zone 6b. 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 | -5.2 °C | 0.7 °C | 59.18 mm |
| February | -4.7 °C | 4.4 °C | 37.85 mm |
| March | -1.9 °C | 10 °C | 51.05 mm |
| April | 1.1 °C | 15.6 °C | 37.85 mm |
| May | 5.3 °C | 21 °C | 42.93 mm |
| June | 8.6 °C | 24.1 °C | 46.48 mm |
| July | 11.3 °C | 29.9 °C | 21.84 mm |
| August | 10.7 °C | 30.2 °C | 13.97 mm |
| September | 6.7 °C | 24.4 °C | 19.81 mm |
| October | 1.7 °C | 14.8 °C | 36.07 mm |
| November | -1.8 °C | 5.8 °C | 61.98 mm |
| December | -5.2 °C | 0.7 °C | 67.06 mm |
| Annual | 2.2 °C | 15.1 °C | 496.07 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |