Cottonwood, Idaho has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.4 °C (low) to 13.9 °C (high). Annual precipitation averages 545.8 Millimeters. Cottonwood is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.3 °C | 2.4 °C | 45.97 mm |
| February | -4.6 °C | 4.7 °C | 37.34 mm |
| March | -2.4 °C | 8.3 °C | 44.96 mm |
| April | 0.2 °C | 12.5 °C | 55.63 mm |
| May | 3.8 °C | 17.2 °C | 71.88 mm |
| June | 6.7 °C | 20.9 °C | 67.56 mm |
| July | 9.9 °C | 27.3 °C | 27.94 mm |
| August | 9.8 °C | 28.2 °C | 22.86 mm |
| September | 5.9 °C | 22.5 °C | 26.16 mm |
| October | 1.3 °C | 14.6 °C | 43.18 mm |
| November | -2.7 °C | 6.3 °C | 52.07 mm |
| December | -5.8 °C | 2.1 °C | 50.29 mm |
| Annual | 1.4 °C | 13.9 °C | 545.84 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 100-125 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 | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |