Alta, Utah has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from -1.6 °C (low) to 9.1 °C (high). Annual precipitation averages 1229.4 Millimeters. Alta is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.1 °C | -0.8 °C | 161.54 mm |
| February | -9.9 °C | -0.7 °C | 147.57 mm |
| March | -7.3 °C | 2.7 °C | 144.53 mm |
| April | -4.8 °C | 6.1 °C | 138.68 mm |
| May | 0.1 °C | 11.3 °C | 100.84 mm |
| June | 5.3 °C | 17.7 °C | 44.7 mm |
| July | 10.1 °C | 22.7 °C | 33.78 mm |
| August | 9.5 °C | 21.9 °C | 48.51 mm |
| September | 5 °C | 16.8 °C | 63.5 mm |
| October | -0.9 °C | 9.6 °C | 91.19 mm |
| November | -6.2 °C | 2.8 °C | 111.76 mm |
| December | -10.2 °C | -1.3 °C | 142.75 mm |
| Annual | -1.6 °C | 9.1 °C | 1229.35 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |