Silverton, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 1.3 °C (low) to 13.7 °C (high). Annual precipitation averages 938 Millimeters. Silverton is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5 °C | 1.4 °C | 115.82 mm |
| February | -4.8 °C | 3.8 °C | 83.57 mm |
| March | -2.7 °C | 8.2 °C | 104.9 mm |
| April | 0.2 °C | 12.9 °C | 76.96 mm |
| May | 3.8 °C | 18.7 °C | 69.85 mm |
| June | 7.1 °C | 22.2 °C | 68.58 mm |
| July | 9.3 °C | 27.8 °C | 26.92 mm |
| August | 8.9 °C | 27.9 °C | 25.65 mm |
| September | 5.3 °C | 22.2 °C | 37.59 mm |
| October | 1.2 °C | 13.3 °C | 87.12 mm |
| November | -2.1 °C | 5.2 °C | 126.24 mm |
| December | -5.1 °C | 0.8 °C | 114.81 mm |
| Annual | 1.3 °C | 13.7 °C | 938.01 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |