Coolin, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 0.3 °C (low) to 13.6 °C (high). Annual precipitation averages 775 Millimeters. Coolin is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.2 °C | 0.5 °C | 96.01 mm |
| February | -6.2 °C | 3.6 °C | 62.74 mm |
| March | -3.7 °C | 8.1 °C | 82.04 mm |
| April | -0.9 °C | 13.2 °C | 59.69 mm |
| May | 3.1 °C | 19 °C | 64.77 mm |
| June | 6.4 °C | 22.2 °C | 64.77 mm |
| July | 8.4 °C | 27.9 °C | 24.89 mm |
| August | 7.8 °C | 28.1 °C | 20.83 mm |
| September | 3.9 °C | 22.2 °C | 29.72 mm |
| October | -0.1 °C | 13.1 °C | 65.28 mm |
| November | -3.1 °C | 4.6 °C | 96.77 mm |
| December | -6.2 °C | 0.3 °C | 107.44 mm |
| Annual | 0.3 °C | 13.6 °C | 774.95 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |