Route reliability record
PDX→SAN
Portland to San Diego
- Flights
- 1,772
- Period
- July 2025 to June 2026
- Distance
- 933 mi
- Carriers
- 3
This route lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 40 minutes on average. That is a workable record, not a spotless one. That rests on 1,772 PDX to SAN flights, with a median arrival 1 minute early.
Best time to fly PDX to SAN: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 83.1% of the time and Saturday flights 86.4%, against 78.9% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.9%
Arrivals under 15 minutes late, of 1,756 completed flights
Avg delay
41 min
Across delayed arrivals only, not all flights
Cancelled
0.79%
National rate is 1.81%
Best carrier
Alaska
78.9% on time across 1,605 flights
These figures cover 1,772 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
Carrier by carrier
Which airline is most reliable on PDX to SAN
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 30 | 90.0% | 68 min | 0.00% | A+ |
| Alaska Airlines | 1,605 | 78.9% | 42 min | 0.87% | B+ |
| Southwest Airlinesthin sample | 137 | 75.9% | 29 min | 0.00% | B+ |
Departure window
The best time of day to leave
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 1,772 flights.
- 5am–8am347 flights83.1%
- 8am–11am339 flights81.2%
- 11am–2pm107 flights75.7%
- 2pm–5pm397 flights78.9%
- 5pm–8pm362 flights74.7%
- 8pm–5am220 flights77.0%
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 83.1% of the time, against 74.7% for the evening window. That is 8 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 397 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 23 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.
December is the weak month at 67.7% on time, against 90.2% in April. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. March was the busiest month here, with 172 flights.
Across the week, Saturday is the strongest day at 86.4% on time and Friday the weakest at 71.6%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 15,000 reported delay minutes.
- 38%National Airspace System
- 34%Late-arriving aircraft
- 28%Carrier
- 1%Extreme weather
- 0%Security
38% 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 5,712 minutes out of 15,000, against a national NAS share of 21%. The split is drawn from 15,100 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 83.1% on time here.
Cancellations are rare at 0.79%, below the national 1.81% 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
Badly late arrivals are rare here: only 3.1% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 933 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 84.1% on time across 1,777 flights, 5 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 5 points of difference.
The sample behind these figures is 1,772 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 SAN 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. April runs 90.2% on time and December 67.7%, a swing of 23 points. If the dates move at all, move them out of December before you think about anything else. 1,756 completed flights over 12 months sit behind that.
Common questions
PDX to SAN questions
How often is PDX to SAN delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.1% of the 1,772 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 40 minutes on average.
How reliable is PDX to SAN compared with the rest of the country?
78.9% of flights arrive on time here against a national 77.6%, a difference of about a point in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on PDX to SAN?
The 5am–8am departure window is the strongest at 83.1% on time. The 5pm–8pm window is the weakest at 74.7%, 8 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 December delays on PDX to SAN?
December is the weakest month at 67.7% on time, compared with 90.2% in April. Across the year that is 23 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
- SAN to PDX — the return legseparate record
- Portland International (PDX) delay statistics
- San Diego International (SAN) delay statistics
- Alaska Airlines on PDX to SAN78.9%
- Southwest Airlines on PDX to SAN75.9%
- PDX to SEA, a related route84.8%
- SFO to SAN, a related route66.6%
- PDX to LAX, a related route87.4%
- SkyWest Airlines on-time record90.0%
- Alaska Airlines on-time record78.9%
- Southwest Airlines on-time record75.9%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. PDX to SAN and SAN 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.