Dayton, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.3 °C (low) to 17.5 °C (high). Annual precipitation averages 1098.3 Millimeters. 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 | 2.1 °C | 8.5 °C | 172.72 mm |
| February | 2.2 °C | 10.6 °C | 124.97 mm |
| March | 3.3 °C | 13.2 °C | 118.11 mm |
| April | 4.9 °C | 15.9 °C | 86.87 mm |
| May | 7.7 °C | 20.1 °C | 54.36 mm |
| June | 10 °C | 23.2 °C | 33.78 mm |
| July | 12 °C | 28.1 °C | 7.11 mm |
| August | 11.9 °C | 28.3 °C | 10.16 mm |
| September | 9.8 °C | 24.8 °C | 33.27 mm |
| October | 6.6 °C | 17.8 °C | 91.19 mm |
| November | 3.8 °C | 11.7 °C | 164.08 mm |
| December | 1.7 °C | 8.1 °C | 201.68 mm |
| Annual | 6.3 °C | 17.5 °C | 1098.3 mm |
| 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 : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |