National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Dangerous Heat and Possible Flooding

Dangerous heat will persist across the Southwest U.S. through Saturday with daytime highs of 110-115°F. Extreme Heat Warnings remain in effect. Dangerous heat will build across the southern Plains again beginning this weekend. Heavy to excessive rain over the Carolinas Friday may lead to isolated areas of flash flooding. Read More >

Current conditions at

Boeing Field - King County International Airport (KBFI)

Lat: 47.54548°NLon: 122.3147°WElev: 20.0ft.

Overcast

61°F

16°C

Humidity 77%
Wind Speed N 0 MPH
Barometer 30.06 in (1017.95 mb)
Dewpoint 54°F (12°C)
Visibility 10.00 mi
Last update 28 Aug 07:20 AM PDT
Extended Forecast for

Mercer Island WASimilar City Names

  • Today

    Today: Cloudy, then gradually becoming mostly sunny, with a high near 73. Light and variable wind.

    High: 73 °F

    Decreasing
    Clouds

  • Tonight

    Tonight: Rain, mainly after 11pm. Low around 56. North wind around 6 mph becoming light and variable. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 56 °F

    Chance Rain
    then Rain

  • Saturday

    Saturday: Rain and thunderstorms before 3pm, then a chance of showers and thunderstorms, mainly between 3pm and 4pm. High near 69. South southeast wind around 5 mph becoming calm in the morning. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 69 °F

    Showers then
    Chance
    Showers

  • Saturday Night

    Saturday Night: A 20 percent chance of rain before 11pm. Mostly cloudy, with a low around 55. Calm wind becoming south around 5 mph after midnight.

    Low: 55 °F

    Slight Chance
    Rain then
    Mostly Cloudy

  • Sunday

    Sunday: Mostly cloudy, with a high near 70. South wind around 5 mph becoming calm in the afternoon.

    High: 70 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 54.

    Low: 54 °F

    Partly Cloudy

  • Monday

    Monday: Partly sunny, with a high near 72.

    High: 72 °F

    Partly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 56.

    Low: 56 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: A slight chance of rain after 11am. Partly sunny, with a high near 71.

    High: 71 °F

    Slight Chance
    Rain

Detailed Forecast

Today
Cloudy, then gradually becoming mostly sunny, with a high near 73. Light and variable wind.
Tonight
Rain, mainly after 11pm. Low around 56. North wind around 6 mph becoming light and variable. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.
Saturday
Rain and thunderstorms before 3pm, then a chance of showers and thunderstorms, mainly between 3pm and 4pm. High near 69. South southeast wind around 5 mph becoming calm in the morning. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday Night
A 20 percent chance of rain before 11pm. Mostly cloudy, with a low around 55. Calm wind becoming south around 5 mph after midnight.
Sunday
Mostly cloudy, with a high near 70. South wind around 5 mph becoming calm in the afternoon.
Sunday Night
Partly cloudy, with a low around 54.
Monday
Partly sunny, with a high near 72.
Monday Night
Mostly cloudy, with a low around 56.
Tuesday
A slight chance of rain after 11am. Partly sunny, with a high near 71.
Tuesday Night
A chance of rain, mainly after 11pm. Mostly cloudy, with a low around 56.
Wednesday
A chance of rain. Mostly cloudy, with a high near 65.
Wednesday Night
A chance of rain. Mostly cloudy, with a low around 54.
Thursday
A chance of rain. Partly sunny, with a high near 66.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Mercer Island WASimilar City Names
 47.58°N 122.22°W (Elev. 118 ft)
Last Update:
11:26 pm PDT Aug 27, 2026
Forecast Valid:
7am PDT Aug 28, 2026-6pm PDT Sep 3, 2026
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation