Packwood, Washington has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 4.5 °C (low) to 15.4 °C (high). Annual precipitation averages 1495.6 Millimeters. Packwood is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -0.5 °C | 6.2 °C | 223.27 mm |
| February | -0.2 °C | 8.4 °C | 157.73 mm |
| March | 1.1 °C | 10.9 °C | 160.02 mm |
| April | 3 °C | 13.7 °C | 103.89 mm |
| May | 6.2 °C | 18.7 °C | 73.91 mm |
| June | 8.8 °C | 21 °C | 54.1 mm |
| July | 10.9 °C | 25.8 °C | 17.53 mm |
| August | 10.8 °C | 26.2 °C | 22.61 mm |
| September | 7.8 °C | 22.8 °C | 52.32 mm |
| October | 4.5 °C | 16 °C | 145.54 mm |
| November | 1.6 °C | 9.3 °C | 243.84 mm |
| December | -0.4 °C | 5.6 °C | 240.79 mm |
| Annual | 4.5 °C | 15.4 °C | 1495.55 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |