Cusick, Washington has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 1 °C (low) to 14.7 °C (high). Annual precipitation averages 619 Millimeters. Cusick 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.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.8 °C | 0.9 °C | 76.2 mm |
| February | -5.5 °C | 4.3 °C | 49.28 mm |
| March | -2.8 °C | 9.4 °C | 64.77 mm |
| April | 0 °C | 14.5 °C | 50.29 mm |
| May | 4.2 °C | 20.2 °C | 52.32 mm |
| June | 7.2 °C | 23.5 °C | 53.09 mm |
| July | 9.4 °C | 29.4 °C | 20.83 mm |
| August | 8.7 °C | 29.6 °C | 16.76 mm |
| September | 4.7 °C | 23.8 °C | 20.57 mm |
| October | 0.4 °C | 14.7 °C | 51.05 mm |
| November | -2.5 °C | 5.6 °C | 75.95 mm |
| December | -5.8 °C | 0.7 °C | 87.88 mm |
| Annual | 1 °C | 14.7 °C | 618.99 mm |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | May 11 - May 20 |
| 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 | Dsb - Humid Continental Climate - Dry Cool Summer |