Twin Falls, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 3.1 °C (low) to 16.9 °C (high). Annual precipitation averages 254.8 Millimeters. Twin Falls is located in USDA Plant Hardiness Zone 6b. 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 | -5.6 °C | 3.3 °C | 29.46 mm |
| February | -4.1 °C | 6.3 °C | 18.29 mm |
| March | -0.8 °C | 11.9 °C | 25.91 mm |
| April | 1.9 °C | 15.6 °C | 27.18 mm |
| May | 6.3 °C | 20.9 °C | 32.51 mm |
| June | 10.1 °C | 26.1 °C | 17.02 mm |
| July | 13.9 °C | 31.8 °C | 4.32 mm |
| August | 12.7 °C | 31 °C | 8.13 mm |
| September | 8.1 °C | 25.5 °C | 11.43 mm |
| October | 2.5 °C | 17.8 °C | 22.61 mm |
| November | -2.3 °C | 9.6 °C | 23.11 mm |
| December | -5.7 °C | 3.3 °C | 34.8 mm |
| Annual | 3.1 °C | 16.9 °C | 254.77 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |