STL to PDX flight delays & on-time performance
Nonstop flights from St. Louis Lambert International Airport to Portland International Airport · 1,708 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at STL or PDX right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from St. Louis (STL) to Portland (PDX) arrived on time 77% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 2.6% were cancelled, and 1% arrived an hour or more late.
- Alaska Airlines was the most punctual airline here (88% on time); Southwest Airlines was the least (52%).
- Friday was the most reliable day to fly (100% on time) and Sunday the least (63%).
- The largest source of delay minutes was late-arriving aircraft (47%).
Which airline is most on time from STL to PDX?
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 | 88% | 2.5% | 4 min | 1.3% | 80 |
| Southwest Airlines | 52% | 2.9% | 17 min | 0.0% | 34 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 2pm70%10 flights
- 5pm84%87 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday91%0.0% cancelled
- Tuesday91%0.0% cancelled
- Wednesday82%8.3% cancelled
- Thursday92%0.0% cancelled
- Friday100%0.0% cancelled
- Saturday63%3.6% cancelled
- Sunday63%3.6% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Late-arriving aircraft47%
- Air traffic control & airport congestion19%
- Airline (crew, maintenance, cleaning, fueling)18%
- Extreme weather12%
- Security5%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)67%
- Extreme weather33%
- Air traffic control & airport congestion0%
- Security0%
STL to PDX: common questions
- How often are STL to PDX flights on time?
- 77% 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 St. Louis to Portland cancelled?
- 2.6% of scheduled flights were cancelled (3 of 114).
- How long are typical delays?
- Across all flights the average arrival delay was 8 min (early arrivals count as zero). Flights that were late arrived 29 min behind schedule on average, and 0.9% of flights were an hour or more late.
- How long is taxi time at STL?
- Flights on this route spent 12 min taxiing from the gate to takeoff on average.
Related routes
Return trip: PDX to STL — 79% on time
More flights from St. Louis
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: STL → PDX, nonstop flights by US airlines that report to the DOT. How we calculate this.