Dayton, Idaho has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.9 °F (low) to 59.4 °F (high). Annual precipitation averages 17 Inches. Dayton 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. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.3 °F | 32.3 °F | 1.87 in. |
| February | 17.7 °F | 37.0 °F | 1.38 in. |
| March | 26.4 °F | 48.5 °F | 1.58 in. |
| April | 32.1 °F | 57.4 °F | 1.82 in. |
| May | 39.2 °F | 66.8 °F | 2.27 in. |
| June | 45.5 °F | 77.5 °F | 1.15 in. |
| July | 52.8 °F | 88.1 °F | 0.64 in. |
| August | 51.3 °F | 86.8 °F | 0.88 in. |
| September | 43.0 °F | 76.6 °F | 1.38 in. |
| October | 33.0 °F | 61.6 °F | 1.67 in. |
| November | 23.6 °F | 45.9 °F | 1.15 in. |
| December | 15.9 °F | 33.7 °F | 1.2 in. |
| Annual | 32.9 °F | 59.4 °F | 16.99 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |