Idaho Springs, Colorado has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.4 °C (low) to 14.1 °C (high). Annual precipitation averages 446.3 Millimeters. Idaho Springs is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.2 °C | 4 °C | 16.26 mm |
| February | -9.4 °C | 4.7 °C | 17.02 mm |
| March | -6.1 °C | 8.8 °C | 34.04 mm |
| April | -3.1 °C | 11.7 °C | 53.85 mm |
| May | 1.3 °C | 16.6 °C | 61.21 mm |
| June | 5.5 °C | 23.1 °C | 43.94 mm |
| July | 8.9 °C | 26.3 °C | 61.98 mm |
| August | 8.1 °C | 25.1 °C | 52.32 mm |
| September | 3.9 °C | 21.4 °C | 40.39 mm |
| October | -1.1 °C | 14.8 °C | 27.94 mm |
| November | -5.7 °C | 8.4 °C | 20.57 mm |
| December | -9.5 °C | 3.8 °C | 16.76 mm |
| Annual | -1.4 °C | 14.1 °C | 446.28 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 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 |