Iliff, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 34.7 °F (low) to 65.1 °F (high). Annual precipitation averages 16.7 Inches. Iliff is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.1 °F | 42.7 °F | 0.29 in. |
| February | 16.1 °F | 44.8 °F | 0.43 in. |
| March | 24.1 °F | 55.3 °F | 0.83 in. |
| April | 31.9 °F | 62.6 °F | 1.75 in. |
| May | 42.9 °F | 71.6 °F | 2.73 in. |
| June | 53.4 °F | 84.1 °F | 2.52 in. |
| July | 59.7 °F | 90.8 °F | 2.54 in. |
| August | 56.5 °F | 88.3 °F | 2.19 in. |
| September | 47.1 °F | 80.0 °F | 1.4 in. |
| October | 33.7 °F | 66.4 °F | 1.15 in. |
| November | 22.6 °F | 53.0 °F | 0.46 in. |
| December | 14.1 °F | 42.0 °F | 0.38 in. |
| Annual | 34.7 °F | 65.1 °F | 16.67 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |