Magna, Utah has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 5.4 °C (low) to 17.8 °C (high). Annual precipitation averages 431 Millimeters. Magna is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.4 °C | 3.7 °C | 32.77 mm |
| February | -3.3 °C | 6.7 °C | 30.99 mm |
| March | 0.9 °C | 12.3 °C | 39.37 mm |
| April | 3.8 °C | 16 °C | 62.23 mm |
| May | 8.5 °C | 21.7 °C | 53.59 mm |
| June | 13.1 °C | 28.1 °C | 40.89 mm |
| July | 18.5 °C | 33.6 °C | 17.78 mm |
| August | 17.2 °C | 32.7 °C | 19.3 mm |
| September | 11.8 °C | 26.5 °C | 29.72 mm |
| October | 5.1 °C | 18.2 °C | 39.37 mm |
| November | -0.9 °C | 10.2 °C | 33.53 mm |
| December | -5 °C | 4 °C | 31.5 mm |
| Annual | 5.4 °C | 17.8 °C | 431.04 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |