Mercer Island weather
Loading live data…Latest for Mercer Island: NWS (National Blend (NBM)): 64° Partly cloudy · American (NOAA GFS): 62° Clear · European (ECMWF): 62° Light drizzle.
The weather map: all three models at once
NWS, American, European side by side around Mercer Island and nearby towns.Live rain radar →Next 14 hours
consensus of the three models7-day forecast
where the models agree, and where they splitMercer Island, WA is at its warmest in Jul (average highs near 79°F) and coldest in Jan (lows around 36°F), with roughly 46 in of precipitation across the year. Below, compare what NWS, American, European forecast for Mercer Island right now, and see exactly where they disagree.
Mercer Island climate by month
average daytime high and overnight low across a typical yearWhich forecast is most accurate in the US?
CheckWeather Score — graded against the weather that actually happened
The CheckWeather Score blends temperature, wind and rain accuracy — each measured against ERA5 (the recorded weather) over the last 30 days across 40 cities. Lower error means a higher score. The apps you know (AccuWeather, Apple Weather, The Weather Channel) are built on these models.
Common questions
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The forecasts Americans check
The two biggest apps keep their model a secret, so we can't show their numbers, only link you to them. The National Weather Service is public, so its data sits right in the comparison above.