Rosedale, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 43.6 °F (low) to 60.8 °F (high). Annual precipitation averages 48.9 Inches. Rosedale is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.7 °F | 47.3 °F | 7.51 in. |
| February | 35.3 °F | 49.9 °F | 4.39 in. |
| March | 37.6 °F | 54.2 °F | 5.4 in. |
| April | 40.8 °F | 59.1 °F | 3.63 in. |
| May | 46.3 °F | 66.0 °F | 2.2 in. |
| June | 50.8 °F | 70.6 °F | 1.52 in. |
| July | 54.3 °F | 76.7 °F | 0.66 in. |
| August | 54.2 °F | 77.1 °F | 1.06 in. |
| September | 50.2 °F | 71.5 °F | 1.77 in. |
| October | 44.2 °F | 59.7 °F | 5.03 in. |
| November | 38.6 °F | 51.7 °F | 7.99 in. |
| December | 35.2 °F | 46.3 °F | 7.78 in. |
| Annual | 43.6 °F | 60.8 °F | 48.94 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 40-50 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 |