Rhododendron, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 3.5 °C (low) to 13.9 °C (high). Annual precipitation averages 2375.9 Millimeters. Rhododendron is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1.8 °C | 4.7 °C | 324.36 mm |
| February | -1.3 °C | 6.9 °C | 233.93 mm |
| March | 0.1 °C | 10 °C | 256.79 mm |
| April | 2 °C | 12.4 °C | 212.6 mm |
| May | 4.9 °C | 16.3 °C | 167.13 mm |
| June | 7.6 °C | 19.3 °C | 112.27 mm |
| July | 10.1 °C | 23.9 °C | 22.86 mm |
| August | 9.9 °C | 24.4 °C | 33.27 mm |
| September | 7.4 °C | 21.2 °C | 92.71 mm |
| October | 3.8 °C | 14.9 °C | 217.42 mm |
| November | 0.6 °C | 8.2 °C | 325.88 mm |
| December | -1.9 °C | 4.2 °C | 376.68 mm |
| Annual | 3.5 °C | 13.9 °C | 2375.9 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |