Weiser, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 4 °C (low) to 18.3 °C (high). Annual precipitation averages 318.5 Millimeters. Weiser is located in USDA Plant Hardiness Zone 7a. 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 | -5.3 °C | 2.7 °C | 45.47 mm |
| February | -3.3 °C | 7.4 °C | 32.77 mm |
| March | 0.2 °C | 13.6 °C | 32.26 mm |
| April | 3.1 °C | 17.9 °C | 24.38 mm |
| May | 7.7 °C | 23.3 °C | 30.73 mm |
| June | 11.4 °C | 28 °C | 24.64 mm |
| July | 15.5 °C | 34.2 °C | 7.11 mm |
| August | 14 °C | 33.3 °C | 4.32 mm |
| September | 8.8 °C | 27.4 °C | 9.65 mm |
| October | 2.8 °C | 18.8 °C | 19.05 mm |
| November | -1.9 °C | 9.5 °C | 34.04 mm |
| December | -5.1 °C | 3.3 °C | 54.1 mm |
| Annual | 4 °C | 18.3 °C | 318.52 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |