Marblemount, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 41.1 °F (low) to 59.6 °F (high). Annual precipitation averages 80.7 Inches. Marblemount 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 Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 32.5 °F | 42.3 °F | 11.45 in. |
| February | 32.7 °F | 46.3 °F | 7.48 in. |
| March | 34.7 °F | 51.7 °F | 8.43 in. |
| April | 38.5 °F | 59.5 °F | 5.59 in. |
| May | 43.9 °F | 66.9 °F | 4.0 in. |
| June | 48.6 °F | 71.2 °F | 3.65 in. |
| July | 51.7 °F | 78.1 °F | 1.74 in. |
| August | 51.8 °F | 79.3 °F | 1.77 in. |
| September | 48.1 °F | 71.9 °F | 3.62 in. |
| October | 41.8 °F | 58.9 °F | 8.31 in. |
| November | 36.0 °F | 47.6 °F | 13.38 in. |
| December | 32.3 °F | 41.4 °F | 11.24 in. |
| Annual | 41.1 °F | 59.6 °F | 80.66 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| 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 8a : 10°F to 15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |