Somerset, Colorado has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.2 °C (low) to 17.1 °C (high). Annual precipitation averages 422.4 Millimeters. Somerset is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.2 °C | 2.8 °C | 36.07 mm |
| February | -8.2 °C | 5.9 °C | 37.08 mm |
| March | -3.9 °C | 11.8 °C | 35.05 mm |
| April | -0.6 °C | 16.3 °C | 43.43 mm |
| May | 3.9 °C | 21.8 °C | 36.58 mm |
| June | 8.3 °C | 28.2 °C | 15.49 mm |
| July | 11.9 °C | 31.4 °C | 32.26 mm |
| August | 11 °C | 29.7 °C | 34.29 mm |
| September | 6.6 °C | 25.4 °C | 47.5 mm |
| October | 0.5 °C | 18.4 °C | 38.35 mm |
| November | -5.3 °C | 10.2 °C | 29.46 mm |
| December | -10.6 °C | 3 °C | 36.83 mm |
| Annual | 0.2 °C | 17.1 °C | 422.39 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 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 | Extreme Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |