Route reliability record
PDX→SFO
Portland to San Francisco
- Flights
- 3,495
- Period
- September 2025 to August 2026
- Distance
- 550 mi
- Carriers
- 3
This route draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 3,495 PDX to SFO flights, of which Alaska Airlines flew 1,403 at 67.4% on time.
Best time to fly PDX to SFO: a 2pm–5pm departure, ideally on a Saturday. Flights in that window arrived on time 75.4% of the time and Saturday flights 76.3%, against 66.8% for the route overall.
The national on-time rate over the same period is 77.3%, so this route runs 11 points behind the country as a whole. Across a thousand flights that is about 105 extra late arrivals.
Key figures
On time
66.8%
Arrivals under 15 minutes late, of 3,480 completed flights
Avg delay
57 min
Across delayed arrivals only, not all flights
Cancelled
0.37%
National rate is 1.89%
Best carrier
Alaska
67.4% on time across 1,403 flights
These figures cover 3,495 flights between September 2025 and August 2026. Beyond the headline rate, 9.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on PDX to SFO
The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 363 | 82.8% | 74 min | 0.55% | B+ |
| Alaska Airlines | 1,403 | 67.4% | 52 min | 0.43% | C+ |
| United Airlines | 1,729 | 62.9% | 58 min | 0.29% | D+ |
No carrier stands out. Alaska tops the table at 67.4%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
Flights on PDX to SFO
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly Portland to San Francisco
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 3 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. PDX → SJCPortland to San Jose | SkyWest Airlines | 87.3% | 87.3% | 0.00% | 5pm–8pm, Wed | — |
| 2. PDX → SJCPortland to San Jose | Southwest Airlines | 76.6% | 76.9% | 0.43% | 5am–8am, Sat | — |
| 3. PDX → OAKPortland to Oakland | Southwest Airlines | 74.1% | 74.7% | 0.78% | 5am–8am, Wed | — |
| 4. PDX → SFOPortland to San Francisco | Alaska Airlines | 67.1% | 67.4% | 0.43% | 2pm–5pm, Sat | AS 526 07:00 |
| 5. PDX → SFOPortland to San Francisco | United Airlines | 62.7% | 62.9% | 0.29% | 2pm–5pm, Sat | UA 2615 19:35 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 15 points, against 5 points between the best and worst carrier.
- 5am–8am1,046 flights67.6%
- 8am–11am514 flights68.8%
- 11am–2pm485 flights60.1%
- 2pm–5pm527 flights75.4%
- 5pm–8pm763 flights61.5%
- 8pm–5am160 flights72.3%
Scale runs 50% to 80%.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 60.1% on time against 75.4% for 2pm–5pm. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 5am–8am window is the busiest, with 1,046 flights scheduled in it.
Explore
Filter PDX to SFO by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On PDX to SFO, the best departure window is 2pm–5pm at 75.4% on time and the worst is 11am–2pm at 60.1%, a wide gap of 15.3 points. All US flights leaving 2pm–5pm ran 71.9%.
- 5–8am67.6%
- 8–11am68.8%
- 11am–2pm60.1%
- 2–5pm75.4%
- 5–8pm61.5%
- 8pm–5am72.3%
best all US flightsScale 50% to 95%.
Across the year
When delays peak on this route
This route's year swings by 45 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 44.2% on time, 45 points below March, the best at 88.9%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. October was the busiest month here, with 343 flights.
Across the week, Saturday is the strongest day at 76.3% on time and Thursday the weakest at 60.9%, a spread of 15 points.
Delay causes
Why this route gets delayed
National Airspace System accounts for 65% of the 66,000 delay minutes carriers reported here, and the remaining four split what is left.
- 65%National Airspace System
- 22%Late-arriving aircraft
- 13%Carrier
- 0%Extreme weather
- 0%Security
65% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 42,000 minutes out of 66,000, against a national NAS share of 21%. The split is drawn from 65,599 reported delay minutes.
Cancellations are rare at 0.37%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here actually costs
9.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 550 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg is a different operation and performs like one: it runs 78.0% on time across 3,491 flights, 11 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 11 points of difference.
The sample behind these figures is 3,495 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in SFO after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 88.9% on time and July 44.2%, a swing of 45 points. If the dates move at all, move them out of July before you think about anything else. 3,480 completed flights over 12 months sit behind that.
Common questions
PDX to SFO questions
How often is PDX to SFO delayed?
About one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 33.2% of the 3,495 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on PDX to SFO?
Alaska Airlines leads at 67.4% on time across 1,403 flights. United Airlines is at the other end on 62.9%, a gap of 5 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on PDX to SFO?
The 2pm–5pm departure window is the strongest at 75.4% on time. The 11am–2pm window is the weakest at 60.1%, 15 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on PDX to SFO?
July is the weakest month at 44.2% on time, compared with 88.9% in March. Across the year that is 45 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- SFO to PDX — the return legseparate record
- Portland International (PDX) delay statistics
- San Francisco International (SFO) delay statistics
- SkyWest Airlines on PDX to SFO82.8%
- Alaska Airlines on PDX to SFO67.4%
- United Airlines on PDX to SFO62.9%
- PDX to SEA, a related route84.9%
- LAX to SFO, a related route60.1%
- PDX to LAX, a related route86.6%
- SkyWest Airlines on-time record82.8%
- Alaska Airlines on-time record67.4%
- United Airlines on-time record62.9%
- How often a connection fails at the major US hubs
- The best time of day to fly, according to 7.05 million flight records
Direction matters. PDX to SFO and SFO to PDX are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.