Hailey, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from -1.6 °C (low) to 13.7 °C (high). Annual precipitation averages 407.2 Millimeters. Hailey is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.3 °C | -0.4 °C | 52.83 mm |
| February | -10.6 °C | 2 °C | 41.15 mm |
| March | -6.1 °C | 6.9 °C | 38.86 mm |
| April | -1.9 °C | 12.6 °C | 32.26 mm |
| May | 2.5 °C | 17.9 °C | 45.72 mm |
| June | 5.7 °C | 22.8 °C | 27.69 mm |
| July | 9.5 °C | 29.2 °C | 6.86 mm |
| August | 8.7 °C | 28.8 °C | 6.35 mm |
| September | 4.4 °C | 23.3 °C | 27.94 mm |
| October | -0.8 °C | 15.4 °C | 27.43 mm |
| November | -6.5 °C | 6.3 °C | 35.31 mm |
| December | -11.4 °C | -0.2 °C | 64.77 mm |
| Annual | -1.6 °C | 13.7 °C | 407.17 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |