Carrier route record
WNPDX→OAK
Southwest Airlines · Portland to Oakland
- Flights
- 1,148
- Period
- September 2025 to August 2026
- Share of route
- 87%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on PDX to OAK sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.3%. The late ones land roughly 50 minutes behind schedule. That rests on 1,148 flights, with a median arrival 2 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Southwest on PDX to OAK from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.7%
Arrivals under 15 minutes late, of 1,139 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.78%
National rate is 1.89%
Whole route
77.2%
Every carrier on PDX to OAK, 1,319 flights
These figures cover 1,148 flights between September 2025 and August 2026. The median arrival is 2 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Carrier by carrier
Southwest against every carrier on PDX to OAK
Southwest flew 1,148 of the 1,319 flights on PDX to OAK, most of the route. Its 74.7% on time is 3 points worse than the route as a whole, which runs 77.2%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Alaska at 100.0% to Southwest at 74.7%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| Alaska Airlinesthin sample | 16 | 100.0% | — | 0.00% | A+ |
| SkyWest Airlinesthin sample | 155 | 92.9% | 42 min | 0.65% | A+ |
| Southwest Airlines (this page) | 1,148 | 74.7% | 48 min | 0.78% | C+ |
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Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 50 points, against half a point between the best and worst carrier.
- 5am–8am314 flights95.2%
- 8am–11am232 flights83.4%
- 11am–2pm123 flights69.9%
- 2pm–5pm143 flights70.9%
- 5pm–8pm211 flights57.6%
- 8pm–5am125 flights45.6%
Scale runs 35% to 100%.
The 8pm–5am window is where this operation falls apart: 45.6% on time, against 95.2% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 314 flights scheduled in it.
Across the year
Southwest on PDX to OAK through the year
July is the worst month at 60.6% on time, 32 points below January, the best at 92.7%. 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 107 flights.
Across the week, Wednesday is the strongest day at 82.0% on time and Sunday the weakest at 68.9%, a spread of 13 points.
Arrival by arrival
How late Southwest on PDX to OAK runs when it is late
The 288 late arrivals split 119 under half an hour, 102 between 30 and 60 minutes, and 67 an hour or more.
- 15+ min early138 flights12.1%
- Within 15 min713 flights62.6%
- 15–29 min late119 flights10.4%
- 30–59 min late102 flights9.0%
- 1–2 hours late52 flights4.6%
- 2+ hours late15 flights1.3%
Scale runs 0% to 100%.
Share of 1,139 completed flights by arrival against schedule.
81 of 338 late departures made up the time and arrived on time, 24% of them. 31 flights left on time and still arrived late.
The worst days
Worst days for Southwest on PDX to OAK
The latest arrival of the period was on 28 December 2025, 4 hours 56 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 28 December 2025 | 4 hours 56 minutes | Carrier |
| 20 July 2026 | 4 hours 45 minutes | Carrier |
| 9 March 2026 | 4 hours | Carrier |
| 19 July 2026 | 4 hours | Carrier |
| 25 February 2026 | 3 hours 44 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 68% of the 14,000 delay minutes carriers reported here, and the remaining four split what is left.
- 68%Late-arriving aircraft
- 27%Carrier
- 5%National Airspace System
- 0%Security
68% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 14,000 reported delay minutes here, that single category outweighs weather by 68 to one. The split is drawn from 13,837 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 95.2% on time here.
Cancellations are rare at 0.78%, 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 costs
5.9% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 50 minutes, which a normal layover absorbs.
The 543 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 78.5% on time across 1,148 flights, 4 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 4 points of difference.
The sample behind these figures is 1,148 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.
What to do with this
Booking Southwest on PDX to OAK
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 92.7% on time and July 60.6%, a swing of 32 points. If the dates move at all, move them out of July before you think about anything else. 1,139 completed flights over 12 months sit behind that.
Related
Where to go next
- PDX to OAK, every carrier
- Southwest on OAK to PDX, the return leg
- SkyWest Airlines on PDX to OAK92.9%
- Southwest Airlines network-wide record
- Portland International (PDX) delay statistics
- Oakland International (OAK) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
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.