The National Weather Service is warning that hot temperatures will continue through Tuesday evening, Aug. 12, 2025 across much of northwest and west-central Washington, including south King County.
The heat advisory, in effect until 10 p.m. Tuesday, Aug. 12, calls for high temperatures in the upper 80s to mid-90s, with overnight lows in the 60s.
Forecasters say the heat poses “a moderate risk of heat-related illness” for those sensitive to high temperatures, especially without cooling or adequate hydration.
“Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors,” the National Weather Service advised. “Young children and pets should never be left unattended in vehicles under any circumstances.”
The NWS said heat will peak Monday along the outer coast and Tuesday for inland areas away from the coast.
The agency urged people who work or spend time outside to “reschedule strenuous activities to early morning or evening” and to “know the signs and symptoms of heat exhaustion and heat stroke.”
The Occupational Safety and Health Administration recommends frequent rest breaks in shaded or air-conditioned environments for outdoor workers. Anyone showing signs of heat stroke should be moved to a cool location, and 911 should be called immediately.
For information on cooling shelters and other human services, residents can dial 211 during business hours or visit wa211.org.
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Michael Snyder of Pacific Northwest Weather Watch reported that a strong ridge of high pressure is keeping much of the region hot, with upper 80s to low 100s recorded across Washington, Oregon, and British Columbia.
Snyder added that a potential frontal system late week that could bring meaningful rain to Western Washington and parts of Oregon.
Here’s his latest forecast:
Detailed Forecast
- Monday: Sunny, with a high near 90. North northwest wind around 9 mph.
- Monday Night: Clear, with a low around 65. North wind 3 to 6 mph.
- Tuesday: Sunny, with a high near 91. Northwest wind 3 to 8 mph.
- Tuesday Night: Mostly clear, with a low around 61. North northwest wind 5 to 7 mph becoming south southwest after midnight.
- Wednesday: Mostly sunny, with a high near 75. South southwest wind 7 to 9 mph.
- Wednesday Night: Partly cloudy, with a low around 58.
- Thursday: Mostly cloudy, with a high near 72.
- Thursday Night: A slight chance of rain after 11pm. Mostly cloudy, with a low around 59.
- Friday: A chance of rain. Cloudy, with a high near 66.
- Friday Night: Rain likely, mainly before 11pm. Mostly cloudy, with a low around 60.
- Saturday: A chance of rain. Mostly cloudy, with a high near 71.
- Saturday Night: A chance of rain. Mostly cloudy, with a low around 58.
- Sunday: A slight chance of rain. Partly sunny, with a high near 73.
(2 of 2) Remember: everyone is at risk from the dangers of extreme heat, but these groups are more vulnerable than most. Ensure that your loved ones and neighbors are safe from the heat and remain Weather-Ready. https://t.co/80tdY5bpNe pic.twitter.com/9CFew6woaa
— NWS Seattle (@NWSSeattle) August 10, 2025
List of 90 degree plus days in Seattle in 10 year increments:
— NWS Seattle (@NWSSeattle) August 11, 2025
1946-55 8
1956-65 31
1966-75 31
1976-85 28
1986-95 40
1996-2005 16
2006-15 49
2016-25 67 ( so far )
Chance for 2 more today and Tuesday before the 70s come back Wednesday. #wawx