Mercer Island, WA Weather Forecast
Local 7-day forecast
Chance Light Rain
Track current conditions, temperature changes, wind, and the full daily outlook for Mercer Island, WA in one place.
A chance of rain. Mostly cloudy, with a high near 61.
Local Weather Overview
This forecast page for Mercer Island, WA is designed for quick trip planning, giving you a clean read on daytime highs, overnight lows, and changing conditions across the upcoming forecast window. Latest sync: Apr 14, 2026 11:51 PM PDT.
The active forecast window currently covers Apr 19 to Apr 21, 2026 for Mercer Island, WA.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Apr 19 to Apr 21, 2026
- Latest sync
- Apr 14, 2026 11:51 PM PDT
- Forecast office
- SEW
- Source
- NOAA / NWS
Daily Outlook
This Week in Mercer Island
Sunday looks like the warmest upcoming period in Mercer Island at 61 degrees F.
Sunday Night is the coolest period ahead with temperatures near 48 degrees F.
The strongest winds are forecast for Sunday at about 3 to 7 mph S.
Precipitation is mentioned in 5 upcoming forecast periods.
Forecast Details
- Last updated
- Apr 14, 2026 11:51 PM PDT
- Coverage
- 3 days
- Time zone
- America/Los_Angeles
- Forecast office
- SEW
- Radar station
- KATX
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
A chance of rain. Mostly cloudy, with a low around 48.
A chance of rain. Partly sunny, with a high near 60.
A chance of rain. Mostly cloudy, with a low around 48.
A chance of rain. Partly sunny, with a high near 59.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Sunday
Apr 19
|
Chance Light Rain
|
61°F |
3 to 7 mph
S
|
|
Sunday Night
Apr 19
|
Chance Light Rain
|
48°F |
3 to 7 mph
NNE
|
|
Monday
Apr 20
|
Chance Light Rain
|
60°F |
3 to 7 mph
N
|
|
Monday Night
Apr 20
|
Chance Light Rain
|
48°F |
3 to 7 mph
SSW
|
|
Tuesday
Apr 21
|
Chance Light Rain
|
59°F |
3 to 7 mph
SSW
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Mercer Island.
