Onaway, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 36.1 °F (low) to 58.1 °F (high). Annual precipitation averages 23.8 Inches. Onaway is located in USDA Plant Hardiness Zone 6b. 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 | 25.5 °F | 36.8 °F | 2.81 in. |
| February | 26.2 °F | 40.7 °F | 2.22 in. |
| March | 29.9 °F | 48.0 °F | 2.4 in. |
| April | 34.5 °F | 55.9 °F | 2.18 in. |
| May | 40.7 °F | 65.4 °F | 2.37 in. |
| June | 45.4 °F | 71.0 °F | 1.73 in. |
| July | 49.0 °F | 82.5 °F | 0.73 in. |
| August | 48.6 °F | 83.8 °F | 0.64 in. |
| September | 42.5 °F | 74.1 °F | 0.87 in. |
| October | 35.6 °F | 59.2 °F | 2.09 in. |
| November | 30.1 °F | 44.2 °F | 2.87 in. |
| December | 24.6 °F | 35.6 °F | 2.92 in. |
| Annual | 36.1 °F | 58.1 °F | 23.83 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |