STL (St. Louis) to PDX (Portland) flights arrive on time 76% of the time. The most reliable airline on this route is Alaska Airlines at 95%. The average delay is 44 minutes. Delays on this route are most often caused by weather.
Source: Bureau of Transportation Statistics. Updated August 2026.STL → PDX
STL (St. Louis) to PDX (Portland)
STL → PDX on-time performance by month
24
25
26
JanFebMarAprMayJunJulAugSepOctNovDec
Worse
Better
This route is on time most of the time. About 76% of flights arrive on schedule.
Delays on this route are most often caused by weather.
Accurate?
Alaska Airlines is significantly more reliable on this route at 95% on time vs Southwest Airlines at 71%.
Airline Comparison
Alaska Airlines leads at 95% on time; Southwest Airlines trails at 71%.
Accurate?
Good to know
Departing from STL
81% on timeTSA is currently ~15 min. Best time: 4 AM (about 5 min).
Arriving at PDX
83% on timeWhen flights into PDX are late, the average delay is 61 minutes. Build buffer if you have ground plans.
If connecting at PDX: TSA is ~11 min right now. Allow at least 60 minutes for a domestic connection.
Flight cancelled or delayed?
Check what Alaska Airlines owes you — refund rights, action plan, complaint email. Free.
Flying out of STL? We'll brief you.
Delays, TSA, weather, gates — we'll let you know if something matters.
Know someone flying soon?
Send them the link — delay data, TSA waits, weather, all free.
Data last updated August 2026. Source: Bureau of Transportation Statistics.