Juliaetta, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 5.4 °C (low) to 17.8 °C (high). Annual precipitation averages 538.5 Millimeters. Juliaetta is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1.2 °C | 5.1 °C | 57.4 mm |
| February | -0.7 °C | 8.2 °C | 50.29 mm |
| March | 1.4 °C | 12.7 °C | 56.39 mm |
| April | 4.2 °C | 17 °C | 55.12 mm |
| May | 7.8 °C | 22.1 °C | 55.63 mm |
| June | 10.9 °C | 25.7 °C | 42.67 mm |
| July | 13.9 °C | 32.3 °C | 14.99 mm |
| August | 13.7 °C | 32.4 °C | 15.49 mm |
| September | 9.9 °C | 26.7 °C | 20.32 mm |
| October | 5.1 °C | 17.7 °C | 43.94 mm |
| November | 1.3 °C | 9.3 °C | 60.71 mm |
| December | -1.6 °C | 4.3 °C | 65.53 mm |
| Annual | 5.4 °C | 17.8 °C | 538.48 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |