Cedar Mill, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.7 °C (low) to 17.3 °C (high). Annual precipitation averages 1069.9 Millimeters. Cedar Mill is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.2 °C | 8.4 °C | 151.89 mm |
| February | 2.2 °C | 10.5 °C | 113.54 mm |
| March | 3.6 °C | 13.2 °C | 117.09 mm |
| April | 5.2 °C | 16.3 °C | 84.33 mm |
| May | 8.3 °C | 20.2 °C | 64.77 mm |
| June | 10.5 °C | 22.9 °C | 43.18 mm |
| July | 12.7 °C | 27.3 °C | 10.67 mm |
| August | 12.8 °C | 27.6 °C | 13.72 mm |
| September | 10.4 °C | 24.3 °C | 38.61 mm |
| October | 6.9 °C | 17.6 °C | 94.74 mm |
| November | 4 °C | 11.4 °C | 155.7 mm |
| December | 1.8 °C | 7.8 °C | 181.61 mm |
| Annual | 6.7 °C | 17.3 °C | 1069.85 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 20-30 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 |