Stanley, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from -6.1 °C (low) to 11.7 °C (high). Annual precipitation averages 432.8 Millimeters. Stanley is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around Jun. 11 - Jun. 20 through the first frost around Year Round Frost.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -15.7 °C | -1.7 °C | 47.75 mm |
| February | -14.7 °C | 1.6 °C | 44.7 mm |
| March | -10.3 °C | 6.1 °C | 41.15 mm |
| April | -5.9 °C | 9.6 °C | 40.89 mm |
| May | -1.8 °C | 15.2 °C | 38.1 mm |
| June | 1.2 °C | 20.1 °C | 29.97 mm |
| July | 3.4 °C | 26.6 °C | 9.65 mm |
| August | 2.3 °C | 26.3 °C | 8.38 mm |
| September | -1.3 °C | 21.1 °C | 18.54 mm |
| October | -4.9 °C | 13.3 °C | 35.56 mm |
| November | -10.1 °C | 4.1 °C | 46.48 mm |
| December | -15.4 °C | -2.3 °C | 71.63 mm |
| Annual | -6.1 °C | 11.7 °C | 432.8 mm |
| Average First Frost Date | Year Round Frost |
| Average Last Frost Date | Jun. 11 - Jun. 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |