Officials warn of dangerous waters during Seattle heat advisory

Published June 12, 2026 5:37 PM PDT

As temperatures hit 80s and 90s over the next few days, officials warn of the dangers of high bacteria levels and dangerously cold waters throughout the region.

What we know:

A heat advisory goes into effect Sunday morning until Tuesday for Western Washington. Temperatures are expected to hit the mid 80s on Sunday and hit a record high Monday at 90 degrees (the previous record high was 88 in 1963.)

If you are planning on cooling off this weekend by taking a dip, officials ask that you take precautions.

What To Know:

Beach closures are in effect at Matthews and Mt Baker Beaches due to high bacteria levels – which means do not swim.

According to Public Health — Seattle and King County, if you swim or wade in water with high levels of bacteria, you can get sick, including: diarrhea, throwing up or nausea, stomach pain, headaches, or fever. It is also possible to get infections in your eyes, ears, nose, throat, or on your skin.

Sign from City of Kirkland tells public to avoid Houghton Beach due to bacterial levels in the water.

While there are other bodies of water that are safe to swim in from bacteria, officials warn water temperatures throughout the region can be dangerous or even deadly.

"This is a beautiful area that offers everything, but the water does not warm up," said Sergeant Rich Barton with the King County Sheriff’s Office.

Barton says air temperatures may be warm, but the water temperature throughout the area will be much colder, around 55 degrees. He says the shock to your system can be deadly.

"You can’t swim. You kind of lock up. The whole body goes rigid, and it’s a fight for life at that point," he said.

people sitting on alki beach

People enjoy relaxing in the soft sand at Alki Beach in West Seattle, Wash.  (FOX 13 Seattle)

There has already been one drowning so far this year at Lake Sammamish State Park, Barton tells FOX 13 Seattle.

He says one way to keep yourself safe is by wearing a life jacket, regardless of how good you are at swimming.

What you can do:

Washington State Parks offer loaner life jackets at 180 different locations throughout the state. The life jackets fit people of all ages and are free to use.

For a map of all the loaner life jacket locations, click here.

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The Source: Information in this story came from Public Health — Seattle and King County, the King County Sheriff’s Office and FOX 13 Seattle reporting.

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