Information: Seafair 2026 on Mercer Island

Seafair returns Friday, July 31, to Sunday, Aug. 2, with a weekend full of festivities, including the popular Blue Angels air shows. Browse the full list of Seafair activities on the event's website.

This event draws thousands of attendees to areas along the Lake Washington shoreline, including Mercer Island. Here's what Islanders and visitors need to know:

Park Impacts

• Groveland Beach Park: The maximum capacity for recreational use will be limited to 500 people on a first-come, first-served basis during Seafair weekend (July 31-Aug 2). No more persons from the general public will be allowed into the park for recreational use while the park is at maximum capacity, as calculated by onsite City staff. Also note that street parking around the park will be unavailable during Seafair weekend.
• Proctor Landing will be closed to the public to allow for first responder use.
• Dogs are not allowed at public swimming areas from May 1 through Sept. 30 each year. 

Logistics Impacts

• The I-90 floating bridge will remain OPEN throughout Seafair weekend. There are no planned closures for the air shows.
• Parks will be crowded and parking will be limited. Remember to arrive early and remain patient to find parking at prime viewing areas and watch for pedestrian traffic. Consider walking or biking to viewing areas for extra ease. 
• If coming from off-Island, consider taking light rail to Mercer Island. Aubrey Davis Park, a prime viewing area, is a short walk from Mercer Island Station.
• Roads will be congested and traffic control may direct vehicles down alternate routes. Drive carefully and allow extra time to get home after the shows.
• Air shows are loud and noise is sporadic. Consider keeping pets inside during airshow practices and performances to prevent runaway pets.

Boating Information:

• Boaters should be mindful of No Wake Zones and restricted boat traffic areas during the event. Familiarize yourself with Washington State boating laws.
• Mercer Island Marine Patrol will be on the lake along with additional vessels from surrounding law enforcement agencies to ensure everyone’s safety in the water and along the coastlines. Call 911 to report emergencies or safety concerns.
• Sober boating enforcement will be in effect throughout Lake Washington. DO NOT drink and operate a vessel.
• The Department of Homeland Security and the U.S. Coast Guard issue unique boating regulations for boaters and swimmers in Lake Washington during Seafair. These include how to interpret air horn signals from the Coast Guard, information on no-go zones, and more. Make sure you're aware of these restrictions and regulations.