Glendale, Colorado has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2 °C (low) to 15.4 °C (high). Annual precipitation averages 554.2 Millimeters. Glendale 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.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.8 °C | 5.6 °C | 18.29 mm |
| February | -6.5 °C | 6.1 °C | 29.97 mm |
| March | -3.4 °C | 9.9 °C | 48.01 mm |
| April | -0.8 °C | 12.9 °C | 82.55 mm |
| May | 4.3 °C | 17.7 °C | 81.03 mm |
| June | 9.3 °C | 24.3 °C | 46.74 mm |
| July | 13.2 °C | 27.8 °C | 59.69 mm |
| August | 12.1 °C | 26.7 °C | 51.05 mm |
| September | 7.9 °C | 22.6 °C | 55.37 mm |
| October | 2.1 °C | 15.6 °C | 36.83 mm |
| November | -2.8 °C | 9.9 °C | 23.37 mm |
| December | -6.2 °C | 5.5 °C | 21.34 mm |
| Annual | 2 °C | 15.4 °C | 554.24 mm |
| Average First Frost Date | Sep.1 - Sep. 10 |
| 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 |