Collbran, Colorado has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.1 °C (low) to 17 °C (high). Annual precipitation averages 373.1 Millimeters. Collbran is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.4 °C | 3.2 °C | 24.13 mm |
| February | -8.2 °C | 6.3 °C | 24.13 mm |
| March | -3.9 °C | 11.8 °C | 35.31 mm |
| April | -0.8 °C | 16 °C | 39.37 mm |
| May | 3.8 °C | 21.7 °C | 38.86 mm |
| June | 8.6 °C | 27.9 °C | 18.29 mm |
| July | 12.2 °C | 31.3 °C | 28.45 mm |
| August | 11.2 °C | 29.9 °C | 33.53 mm |
| September | 6.6 °C | 25.5 °C | 39.88 mm |
| October | 0 °C | 17.9 °C | 39.62 mm |
| November | -5.7 °C | 9.8 °C | 26.92 mm |
| December | -10.9 °C | 3.1 °C | 24.64 mm |
| Annual | 0.1 °C | 17 °C | 373.13 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |