STL → SEA: cancellations & delays
Over Jan 2023 - Apr 2026, 0.9% of St. Louis Lambert International Airport (STL) to Seattle–Tacoma International Airport (SEA) flights were cancelled and 19.0% arrived at least 15 minutes late, across 2,740 flights, flown by AS, WN. Cancellations peak in January.
Check today's live STL departures →Airport pages: St. Louis Lambert International Airport (STL) · Seattle–Tacoma International Airport (SEA)
Rates are historical averages from U.S. DOT (BTS) on-time records; a specific flight's live estimate can differ with weather and the day's disruptions.