Lake Swimming Beach Bacteria and Temperature

We test the water at more than two dozen popular lake swimming beaches during mid-May to mid-September. If water tests find high bacteria, this means there is poop in the water from people, pets, or wildlife. Poop can carry germs that can make people sick from swimming or playing in the water. The information below shows the latest status of these beaches from Public Health – Seattle & King County.

Visit Public Health’s Water Safety website for lifeguard locations and hours, life jackets, cold water safety, and more. For marine beach bacteria, visit Washington's Beach Monitoring website. For toxic algae in lakes, visit the Northwest Toxic Algae website.

Sign up for our email lists:

• Get one Lake Beach Alert every time Public Health closes or reopens a beach.
• Get one Weekly Beach Status email on Friday afternoons.