December travel from Philadelphia (All Airports) (PHLA) to Seattle (All Airports) (SEAA) blends holiday demand with winter weather factors. Book flights early—especially for nonstops—and watch for added seasonal services or premium weekend fares. Search for 'cheap flights PHL to SEA December' and set fare alerts; flexible midweek departures typically save money. Expect longer security lines at Philadelphia International and consider public transit or off-site parking to avoid holiday traffic. For connections, common hubs include Detroit, Chicago, and Minneapolis. Nearby major cities served by PHLA include New York City, Baltimore, and Washington, D.C., so consider alternate routing through those metros if schedules are tight.
Arriving at Seattle (All Airports) (SEAA) in December means planning for rain, shorter daylight hours, and holiday crowds. Use light rail from main terminals where available to reach downtown Seattle quickly, or pre-book a shuttle to Bellevue, Tacoma or Everett. Expect longer waits at ground transportation and baggage claim during peak holiday windows; keep flexible onward connections to Portland or Vancouver and search for 'Seattle airport pickup December' for the latest options. If you plan to visit ski destinations in the Cascades, allow extra time for winter road conditions when booking transfers from SEA.