Broomfield, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 37.4 °F (low) to 65.2 °F (high). Annual precipitation averages 16.8 Inches. Broomfield is located in USDA Plant Hardiness Zone 6a. 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 | 19.9 °F | 46.0 °F | 0.57 in. |
| February | 21.0 °F | 46.9 °F | 0.69 in. |
| March | 28.4 °F | 55.7 °F | 1.56 in. |
| April | 34.5 °F | 61.5 °F | 2.34 in. |
| May | 43.6 °F | 70.3 °F | 2.62 in. |
| June | 52.9 °F | 82.6 °F | 1.52 in. |
| July | 59.1 °F | 88.8 °F | 1.83 in. |
| August | 57.1 °F | 86.6 °F | 1.6 in. |
| September | 48.8 °F | 78.7 °F | 1.38 in. |
| October | 36.9 °F | 65.7 °F | 1.28 in. |
| November | 27.3 °F | 53.9 °F | 0.84 in. |
| December | 19.8 °F | 45.3 °F | 0.58 in. |
| Annual | 37.4 °F | 65.2 °F | 16.81 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |