Dayton, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 43.4 °F (low) to 63.5 °F (high). Annual precipitation averages 43.2 Inches. Dayton is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.7 °F | 47.3 °F | 6.8 in. |
| February | 35.9 °F | 51.1 °F | 4.92 in. |
| March | 37.9 °F | 55.8 °F | 4.65 in. |
| April | 40.8 °F | 60.7 °F | 3.42 in. |
| May | 45.9 °F | 68.1 °F | 2.14 in. |
| June | 50.0 °F | 73.7 °F | 1.33 in. |
| July | 53.6 °F | 82.5 °F | 0.28 in. |
| August | 53.5 °F | 83.0 °F | 0.4 in. |
| September | 49.7 °F | 76.7 °F | 1.31 in. |
| October | 43.8 °F | 64.0 °F | 3.59 in. |
| November | 38.8 °F | 53.0 °F | 6.46 in. |
| December | 35.1 °F | 46.5 °F | 7.94 in. |
| Annual | 43.4 °F | 63.5 °F | 43.24 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |