Silverton, Colorado has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from -6 °C (low) to 11.6 °C (high). Annual precipitation averages 611.9 Millimeters. Silverton is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around Jun. 11 - Jun. 20 through the first frost around Aug. 1 - Aug. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -17.3 °C | 1.3 °C | 46.23 mm |
| February | -15.9 °C | 2.9 °C | 48.51 mm |
| March | -11.3 °C | 6.6 °C | 52.58 mm |
| April | -6.5 °C | 9.6 °C | 40.89 mm |
| May | -1.9 °C | 14.7 °C | 45.47 mm |
| June | 1.8 °C | 20.8 °C | 26.92 mm |
| July | 5.2 °C | 23.3 °C | 61.47 mm |
| August | 4.8 °C | 21.8 °C | 78.23 mm |
| September | 1.1 °C | 18.5 °C | 75.69 mm |
| October | -4.3 °C | 12.7 °C | 57.15 mm |
| November | -11 °C | 6.4 °C | 39.37 mm |
| December | -16.8 °C | 0.9 °C | 39.37 mm |
| Annual | -6 °C | 11.6 °C | 611.88 mm |
| Average First Frost Date | Aug. 1 - Aug. 10 |
| Average Last Frost Date | Jun. 11 - Jun. 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |