Morrison, Colorado has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.6 °F (low) to 63.9 °F (high). Annual precipitation averages 19.7 Inches. Morrison is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.5 °F | 45.5 °F | 0.74 in. |
| February | 19.1 °F | 46.5 °F | 0.95 in. |
| March | 26.5 °F | 54.5 °F | 1.85 in. |
| April | 32.6 °F | 60.0 °F | 2.91 in. |
| May | 41.7 °F | 68.7 °F | 2.86 in. |
| June | 50.8 °F | 80.7 °F | 1.85 in. |
| July | 57.1 °F | 86.7 °F | 1.99 in. |
| August | 55.2 °F | 84.3 °F | 1.69 in. |
| September | 46.9 °F | 77.0 °F | 1.58 in. |
| October | 35.1 °F | 64.3 °F | 1.39 in. |
| November | 25.8 °F | 53.2 °F | 1.08 in. |
| December | 18.1 °F | 44.8 °F | 0.85 in. |
| Annual | 35.6 °F | 63.9 °F | 19.74 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |