Metaline, Washington has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.6 °C (low) to 14 °C (high). Annual precipitation averages 744.5 Millimeters. Metaline is located in USDA Plant Hardiness Zone 6a. 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 | -5.8 °C | 0.2 °C | 77.47 mm |
| February | -5 °C | 3.9 °C | 54.86 mm |
| March | -2.7 °C | 8.8 °C | 65.02 mm |
| April | 0.4 °C | 14.3 °C | 59.94 mm |
| May | 4.8 °C | 19.7 °C | 67.82 mm |
| June | 8.1 °C | 22.9 °C | 82.3 mm |
| July | 10.3 °C | 28.6 °C | 35.56 mm |
| August | 9.8 °C | 29 °C | 22.86 mm |
| September | 5.8 °C | 22.9 °C | 31.75 mm |
| October | 1.6 °C | 13.4 °C | 65.02 mm |
| November | -2.3 °C | 4.7 °C | 94.23 mm |
| December | -5.8 °C | 0.1 °C | 87.63 mm |
| Annual | 1.6 °C | 14 °C | 744.46 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | Over 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 |