Glenwood, Washington has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 35 °F (low) to 59.3 °F (high). Annual precipitation averages 31.4 Inches. Glenwood is located in USDA Plant Hardiness Zone 7a. 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 | 25.3 °F | 38.6 °F | 5.38 in. |
| February | 26.3 °F | 43.4 °F | 3.82 in. |
| March | 29.6 °F | 50.2 °F | 3.27 in. |
| April | 32.6 °F | 56.9 °F | 1.65 in. |
| May | 38.4 °F | 66.5 °F | 1.31 in. |
| June | 43.1 °F | 72.1 °F | 0.72 in. |
| July | 48.0 °F | 82.1 °F | 0.21 in. |
| August | 47.4 °F | 82.7 °F | 0.25 in. |
| September | 41.0 °F | 74.4 °F | 0.75 in. |
| October | 34.2 °F | 60.5 °F | 2.42 in. |
| November | 29.2 °F | 46.3 °F | 4.7 in. |
| December | 25.1 °F | 37.6 °F | 6.9 in. |
| Annual | 35 °F | 59.3 °F | 31.38 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |