Lewisville, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -1.1 °C (low) to 13.7 °C (high). Annual precipitation averages 260.1 Millimeters. Lewisville is located in USDA Plant Hardiness Zone 5a. 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 °C | -2 °C | 19.81 mm |
| February | -10 °C | 0.7 °C | 13.46 mm |
| March | -4.7 °C | 7.9 °C | 19.81 mm |
| April | -1.2 °C | 13.8 °C | 25.91 mm |
| May | 3.2 °C | 18.8 °C | 41.66 mm |
| June | 6.8 °C | 23.6 °C | 28.7 mm |
| July | 9.8 °C | 29.3 °C | 13.21 mm |
| August | 8.7 °C | 29.1 °C | 15.49 mm |
| September | 4.4 °C | 23.3 °C | 22.1 mm |
| October | -0.9 °C | 15.2 °C | 23.62 mm |
| November | -6.1 °C | 6 °C | 15.75 mm |
| December | -11 °C | -1.2 °C | 20.57 mm |
| Annual | -1.1 °C | 13.7 °C | 260.09 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 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |