Smiths Ferry, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from -2.1 °C (low) to 13.8 °C (high). Annual precipitation averages 689.4 Millimeters. Smiths Ferry is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Jun. 11 - Jun. 20 through the first frost around Sep.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.6 °C | 0.7 °C | 94.23 mm |
| February | -9.5 °C | 3.6 °C | 69.09 mm |
| March | -6.2 °C | 7.9 °C | 78.74 mm |
| April | -2.8 °C | 12.1 °C | 60.2 mm |
| May | 1.2 °C | 17.4 °C | 63.5 mm |
| June | 4.3 °C | 22.3 °C | 43.18 mm |
| July | 7.7 °C | 28.9 °C | 12.7 mm |
| August | 6.8 °C | 28.6 °C | 12.45 mm |
| September | 2.5 °C | 23.2 °C | 23.37 mm |
| October | -2.1 °C | 14.7 °C | 47.5 mm |
| November | -5.9 °C | 5.8 °C | 75.69 mm |
| December | -10.2 °C | 0.2 °C | 108.71 mm |
| Annual | -2.1 °C | 13.8 °C | 689.36 mm |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | Jun. 11 - Jun. 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 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |