Magnuson Beach

Seattle, Washington

Discover a great urban park which includes pieces of Seattle’s military past and eco-friendly future! Warren G. Magnuson Park sits on a splendid mile-long stretch of Lake Washington’s shoreline in northeast Seattle. At 350 acres, it is Seattle’s second largest park.

This former Navy airfield has transformed into a unique combination of features and activities for you to enjoy: recreation and leisure—boating, tennis, swimming, walks, kite flying, to name a few; sports fields; natural areas; and a historic campus.

COVID-19

Keep your distance from other people.

Practicing social distancing is essential right now. Follow the advice of the health experts. If your community has asked that you remain indoors and away from others, do so. Heading to the beach should only be considered an option if social distancing practices can be followed. Spending a day in any crowded place is the worst thing we can do for our most vulnerable right now and will counter the efforts to curb the virus’ spread.

For more information, please visit the World Health Organization public resource on COVID-19.

Water Quality
  • Meets water quality standards

  • Current Status
  • This status is based on the latest sample, taken on July 28th, 2020. King County Department Natural Resources and Parks updates the status of this beach as soon as test results become available. These results were posted to Swim Guide on July 31st, 2020 at 11:38 AM.
For water quality icon legend, click:  
Current Weather
13°C
A mix of sun and clouds
Monitoring Frequency

Magnuson Beach is sampled weekly from May 15th to September 21st.

Source Information

The King County Department of Natural Resources and Parks monitors water quality at designated swimming beaches in the county from May to September. Water quality data is collected weekly, usually on Mondays. Results are generally posted to the King County Swimming Beach Bacteria Monitoring page by noon on Wednesday.

During the sampling period, Puget Soundkeeper Alliance regularly updates the Swim Guide to reflect the most current information. Local health officials use the following protocol to make closure determinations – A day’s average E. coli value is over 1000 CFU/100 mL – OR - The average of the E. coli values for the three most recent sampling days is over 200 CFU/100 mL. The three-day average is calculated using the geometric mean (geomean). The unit of measure is a CFU which stands for Colony Forming Units.

A beach is marked Green (open) when both of these protocols are met.
A beach is marked Red (closed) when these criteria are not met and the public health officials have closed the beach.

A beach may also be marked Red if there is a Harmful Algal Bloom (HAB) reported at the beach. A beach is marked Grey when current water quality data is not available. The King County Water and Land Resources Division (WLRD) collects and analyzes the samples. Public Health Seattle & King County is alerted when bacteria or state algal toxin thresholds are exceeded and determines the health and safety implications of the bacteria and algal toxin data collected, and they work with King County WLRD and the local park manager to post an advisory.

For more information go to King County Swimming Beach Bacteria Monitoring website: kingcounty.gov/swimbeach.

Water Quality Graph

Magnuson Beach

Seattle, Washington

COVID-19

Keep your distance from other people.

Practicing social distancing is essential right now. Follow the advice of the health experts. If your community has asked that you remain indoors and away from others, do so. Heading to the beach should only be considered an option if social distancing practices can be followed. Spending a day in any crowded place is the worst thing we can do for our most vulnerable right now and will counter the efforts to curb the virus’ spread.

For more information, please visit the World Health Organization public resource on COVID-19.

Water Quality
  • Meets water quality standards
  • Current Status
  • This status is based on the latest sample, taken on July 28th, 2020. King County Department Natural Resources and Parks updates the status of this beach as soon as test results become available. These results were posted to Swim Guide on July 31st, 2020 at 11:38 AM.
For water quality icon legend, click:  
Current Weather
13°C
A mix of sun and clouds

Discover a great urban park which includes pieces of Seattle’s military past and eco-friendly future! Warren G. Magnuson Park sits on a splendid mile-long stretch of Lake Washington’s shoreline in northeast Seattle. At 350 acres, it is Seattle’s second largest park.

This former Navy airfield has transformed into a unique combination of features and activities for you to enjoy: recreation and leisure—boating, tennis, swimming, walks, kite flying, to name a few; sports fields; natural areas; and a historic campus.

Monitoring Frequency

Magnuson Beach is sampled weekly from May 15th to September 21st.

Source Information

The King County Department of Natural Resources and Parks monitors water quality at designated swimming beaches in the county from May to September. Water quality data is collected weekly, usually on Mondays. Results are generally posted to the King County Swimming Beach Bacteria Monitoring page by noon on Wednesday.

During the sampling period, Puget Soundkeeper Alliance regularly updates the Swim Guide to reflect the most current information. Local health officials use the following protocol to make closure determinations – A day’s average E. coli value is over 1000 CFU/100 mL – OR - The average of the E. coli values for the three most recent sampling days is over 200 CFU/100 mL. The three-day average is calculated using the geometric mean (geomean). The unit of measure is a CFU which stands for Colony Forming Units.

A beach is marked Green (open) when both of these protocols are met.
A beach is marked Red (closed) when these criteria are not met and the public health officials have closed the beach.

A beach may also be marked Red if there is a Harmful Algal Bloom (HAB) reported at the beach. A beach is marked Grey when current water quality data is not available. The King County Water and Land Resources Division (WLRD) collects and analyzes the samples. Public Health Seattle & King County is alerted when bacteria or state algal toxin thresholds are exceeded and determines the health and safety implications of the bacteria and algal toxin data collected, and they work with King County WLRD and the local park manager to post an advisory.

For more information go to King County Swimming Beach Bacteria Monitoring website: kingcounty.gov/swimbeach.

Water Quality Graph

  Beach Location Water Quality
Kirkland, Washington
Seattle, Washington
Seattle, Washington
Kirkland, Washington
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