coastal destination · warmest in Aug · sea ~12°C in July · mid-range
Open Mercer Island on the live value map →| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg °C | 4 | 6 | 7 | 10 | 13 | 16 | 18 | 19 | 16 | 11 | 7 | 4 |
| Sea °C | 8 | 8 | 8 | 9 | 10 | 11 | 12 | 12 | 11 | 10 | 9 | 8 |
| Rain (days) | 135 | 106 | 104 | 75 | 50 | 42 | 25 | 31 | 46 | 84 | 147 | 159 |
Warmest month: Aug. Driest: Jul.