PDX to STL flight delays & on-time performance
Nonstop flights from Portland International Airport to St. Louis Lambert International Airport · 1,708 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at PDX or STL right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Portland (PDX) to St. Louis (STL) arrived on time 79% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 0.9% were cancelled, and 1% arrived an hour or more late.
- Alaska Airlines was the most punctual airline here (81% on time); Southwest Airlines was the least (76%).
- Monday was the most reliable day to fly (91% on time) and Tuesday the least (73%).
- The largest source of delay minutes was air traffic control & airport congestion (51%).
Which airline is most on time from PDX to STL?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| Alaska Airlines | 81% | 1.3% | 7 min | 0.0% | 80 |
| Southwest Airlines | 76% | 0.0% | 8 min | 2.9% | 34 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
Not enough departures across different hours to compare.
Best day of the week
On-time arrival rate by day of departure.
- Monday91%0.0% cancelled
- Tuesday73%0.0% cancelled
- Wednesday82%8.3% cancelled
- Thursday83%0.0% cancelled
- Friday83%0.0% cancelled
- Saturday78%0.0% cancelled
- Sunday75%0.0% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Air traffic control & airport congestion51%
- Airline (crew, maintenance, cleaning, fueling)25%
- Late-arriving aircraft23%
- Extreme weather0%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)100%
- Extreme weather0%
- Air traffic control & airport congestion0%
- Security0%
PDX to STL: common questions
- How often are PDX to STL flights on time?
- 79% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Portland to St. Louis cancelled?
- 0.9% of scheduled flights were cancelled (1 of 114).
- How long are typical delays?
- Across all flights the average arrival delay was 7 min (early arrivals count as zero). Flights that were late arrived 24 min behind schedule on average, and 0.9% of flights were an hour or more late.
- How long is taxi time at PDX?
- Flights on this route spent 20 min taxiing from the gate to takeoff on average.
Related routes
Return trip: STL to PDX — 77% on time
More flights from Portland
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: PDX → STL, nonstop flights by US airlines that report to the DOT. How we calculate this.