This page captures ADS-B flight data for Seattle-Tacoma International Airport (SEA/KSEA) on September 25, 2025, visualized on the 20th anniversary of the airport's major terminal expansion completion. The dataset covers 1,217 total flights across the full 24-hour period, split almost evenly between 608 arrivals and 609 departures, operated by 513 unique aircraft. Traffic was active from midnight through 23:59 PDT, averaging 50.7 flights per hour across the day. The busiest single hour was 20:00-21:00, which recorded 91 movements (55 arrivals and 36 departures). A secondary peak runs through the midday window, with hours 8 through 14 each logging between 66 and 79 flights. The overnight hours from 00:00 to 04:00 were the quietest, with single-digit or low double-digit totals. The top route by total movements was Los Angeles (LAX) with 41 flights, followed by San Francisco (SFO) at 37 and Portland (PDX) at 35. Spokane (GEG) and Phoenix (PHX) round out the top five. Vancouver (YVR) was the only international airport in the top ten, accounting for 28 combined movements. Approach and departure directions were dominated by easterly headings. East was the most common direction for both arrivals (132) and departures (143), with SSE and S also appearing frequently across both categories. Aircraft registered to the United States accounted for 472 of the 513 unique aircraft, with Canadian-registered aircraft second at 9. The altitude distribution shows two concentration points. The 0-1,000 ft band recorded 149,937 ADS-B position points, reflecting departure climbs and arrival descents near the airport. A second concentration sits between 35,000 and 38,000 ft, where the three busiest bands logged 62,286, 58,347, and 54,565 points respectively. The highest recorded altitude was 46,875 ft, reached by tail number N915QS on an arrival from Scottsdale (SCF). The longest flight in the dataset was an arrival from Boston Logan (BOS), covering 3,276.1 nautical miles over 594.7 minutes. At the other end, the shortest recorded flight covered just 4.1 nautical miles. Average groundspeed across all flights was 264 knots, with a maximum of 582.8 knots. Total distance flown across all tracked legs was 978,481 nautical miles.