Glendale, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 40.4 °F (low) to 66.3 °F (high). Annual precipitation averages 39.5 Inches. Glendale is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 31.3 °F | 46.9 °F | 6.66 in. |
| February | 31.9 °F | 53.6 °F | 4.82 in. |
| March | 34.2 °F | 58.2 °F | 4.65 in. |
| April | 37.9 °F | 62.5 °F | 3.13 in. |
| May | 43.1 °F | 71.2 °F | 1.92 in. |
| June | 48.1 °F | 78.3 °F | 0.89 in. |
| July | 54.0 °F | 87.8 °F | 0.36 in. |
| August | 53.1 °F | 88.3 °F | 0.29 in. |
| September | 46.4 °F | 81.7 °F | 0.73 in. |
| October | 38.4 °F | 68.4 °F | 2.51 in. |
| November | 34.8 °F | 53.4 °F | 5.79 in. |
| December | 31.4 °F | 45.0 °F | 7.79 in. |
| Annual | 40.4 °F | 66.3 °F | 39.54 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |