Green Mountain Falls, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -2.4 °C (low) to 14.2 °C (high). Annual precipitation averages 573.3 Millimeters. Green Mountain Falls is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Aug. 21 - Aug. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.2 °C | 4.4 °C | 17.78 mm |
| February | -11.3 °C | 4.7 °C | 20.83 mm |
| March | -7.4 °C | 9.1 °C | 42.93 mm |
| April | -3.9 °C | 12 °C | 63.25 mm |
| May | 0.9 °C | 16.9 °C | 70.87 mm |
| June | 5.8 °C | 23.4 °C | 50.55 mm |
| July | 9 °C | 26.1 °C | 88.9 mm |
| August | 8.3 °C | 24.8 °C | 91.69 mm |
| September | 3.8 °C | 21.4 °C | 59.44 mm |
| October | -2.2 °C | 14.9 °C | 27.43 mm |
| November | -7.7 °C | 8.9 °C | 21.34 mm |
| December | -12.1 °C | 4.3 °C | 18.29 mm |
| Annual | -2.4 °C | 14.2 °C | 573.3 mm |
| Average First Frost Date | Aug. 21 - Aug. 31 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |