Ephraim, Utah has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -0.1 °C (low) to 17.1 °C (high). Annual precipitation averages 297.2 Millimeters. Ephraim is located in USDA Plant Hardiness Zone 5b. 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 | -10.6 °C | 2.7 °C | 23.88 mm |
| February | -7.6 °C | 5.8 °C | 25.15 mm |
| March | -3.6 °C | 11.7 °C | 28.96 mm |
| April | -0.9 °C | 15.4 °C | 28.7 mm |
| May | 3.1 °C | 21 °C | 31.75 mm |
| June | 7.3 °C | 27.7 °C | 17.78 mm |
| July | 11.4 °C | 31.9 °C | 15.49 mm |
| August | 10.6 °C | 30.8 °C | 20.57 mm |
| September | 5.6 °C | 26 °C | 27.18 mm |
| October | -0.4 °C | 18.5 °C | 27.43 mm |
| November | -5.7 °C | 10.3 °C | 22.1 mm |
| December | -10.3 °C | 3.1 °C | 28.19 mm |
| Annual | -0.1 °C | 17.1 °C | 297.18 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 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |