Republic, Washington has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.1 °C (low) to 13.5 °C (high). Annual precipitation averages 462.8 Millimeters. Republic is located in USDA Plant Hardiness Zone 6a. 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 | -7.9 °C | -0.8 °C | 41.4 mm |
| February | -7.3 °C | 3.1 °C | 32 mm |
| March | -3.8 °C | 8.4 °C | 39.88 mm |
| April | -0.8 °C | 13.9 °C | 35.31 mm |
| May | 3.5 °C | 19.3 °C | 51.31 mm |
| June | 6.6 °C | 22.6 °C | 55.88 mm |
| July | 8.9 °C | 28 °C | 31.5 mm |
| August | 8.2 °C | 28.3 °C | 17.02 mm |
| September | 4.2 °C | 22.8 °C | 20.07 mm |
| October | -0.4 °C | 13.6 °C | 30.99 mm |
| November | -4.2 °C | 4.1 °C | 49.28 mm |
| December | -7.9 °C | -1.2 °C | 58.17 mm |
| Annual | -0.1 °C | 13.5 °C | 462.81 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |