Seattle-Tacoma International Airport announces summer construction plans

The Alaska Airlines counter at Sea-Tac Airport on Monday, Jan. 8

SEATTLE — Construction is ongoing at Seattle-Tacoma International Airport (SEA), with a noticeable 120 projects underway as of this summer.

The work is part of Upgrade SEA, an airport modernization plan investing $5 billion over the next five years to make improvements and enhance airport services.

SEA reassured travelers that construction efforts will not hinder customer service experiences, and shared a few recently completed projects, including new dining and retail spaces, renovated restrooms, and parking upgrades.

The airport highlighted construction improvements to security checkpoints, including lane additions to TSA Security Checkpoint 2 and TSA Security Checkpoint 3, set to be completed in early June.

“Overall, the four new lanes will add an additional 600 passengers per hour to overall throughput, helping SEA to meet peak periods of departing passengers this summer.”

Construction projects that will impact travelers this summer include:

  • Those arriving along the north expressway will notice two retaining walls going up as part of the Roadway Improvements project. These will shift the roadway west to accommodate two new lanes.
  • New scaffolding in front of TSA Security Checkpoint 5 is now in place as part of the next phase of the SEA Gateway project.
  • Expanded construction walls are up for the new TSA Security Checkpoint 1 Relocation on the south end of the baggage level of the main terminal in the Arrivals Hall.
  • The C Concourse Expansion has closed dining and retail locations along the beginning of the concourse as four new stories are being built above the space, to open in 2026.

SEA also outlined their forecast for the busiest travel periods over the next couple of weeks. The airport expects an estimated 760,000 passengers to travel through the airport over Memorial Day weekend, close to record numbers.

Over the summer, SEA is forecasting 15.5 million passengers, which is almost equal to 2019 levels. A small bump in demand could make it a record summer.

Mornings before noon are predicted to be consistently busy, with early mornings before 9:00 a.m. as the peak. Busy periods can cause busy conditions at TSA security checkpoints and on the drive over.

Arriving early is recommended, and passengers who arrive early are encouraged to participate in a special 75th Anniversary summer scavenger hunt highlighting some of the most loved places around the airport.

To read more about construction plans at SEA and find a comprehensive list of airport travel tips for passengers ahead of the busy season, visit the Port of Seattle webpage.