Brookside, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 3 °C (low) to 19.5 °C (high). Annual precipitation averages 327.2 Millimeters. Brookside is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.9 °C | 8.9 °C | 15.75 mm |
| February | -6.4 °C | 9.5 °C | 11.43 mm |
| March | -2.5 °C | 14.3 °C | 24.89 mm |
| April | 1.3 °C | 18.1 °C | 42.42 mm |
| May | 6.6 °C | 22.9 °C | 41.4 mm |
| June | 11.7 °C | 29.3 °C | 24.13 mm |
| July | 15.1 °C | 31.7 °C | 55.63 mm |
| August | 14.2 °C | 30.3 °C | 41.66 mm |
| September | 9.5 °C | 26.8 °C | 25.4 mm |
| October | 2.6 °C | 20.3 °C | 18.54 mm |
| November | -2.6 °C | 13.6 °C | 15.24 mm |
| December | -6.6 °C | 8.8 °C | 10.67 mm |
| Annual | 3 °C | 19.5 °C | 327.16 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |