Metaline Falls, Washington has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.8 °C (low) to 13.6 °C (high). Annual precipitation averages 737.9 Millimeters. Metaline Falls is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.6 °C | 0.1 °C | 76.45 mm |
| February | -5.8 °C | 3.9 °C | 55.12 mm |
| March | -3.5 °C | 8.2 °C | 66.55 mm |
| April | -0.3 °C | 13.7 °C | 56.13 mm |
| May | 3.9 °C | 19.2 °C | 67.56 mm |
| June | 7.3 °C | 22.3 °C | 78.99 mm |
| July | 9.6 °C | 28 °C | 36.83 mm |
| August | 9 °C | 28.4 °C | 22.86 mm |
| September | 4.9 °C | 22.3 °C | 30.48 mm |
| October | 0.7 °C | 12.9 °C | 64.26 mm |
| November | -3.1 °C | 4.4 °C | 92.71 mm |
| December | -6.6 °C | 0 °C | 89.92 mm |
| Annual | 0.8 °C | 13.6 °C | 737.86 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |