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DelayAtlas

Carrier route record

WNOAKPDX

Southwest Airlines · Oakland to Portland

Flights
1,181
Period
July 2025 to June 2026
Share of route
91%
Carriers
3
B+GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.

Southwest on OAK to PDX 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 roughly 55 minutes on average. That is a workable record, not a spotless one. That rests on 1,181 flights, with a median arrival 4 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Southwest on OAK to PDX 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 1,176 completed flights

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

0.42%

National rate is 1.81%

Whole route

79.6%

Every carrier on OAK to PDX, 1,297 flights

These figures cover 1,181 flights between July 2025 and June 2026. The median arrival is 4 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.

Carrier by carrier

Southwest against every carrier on OAK to PDX

Southwest flew 1,181 of the 1,297 flights on OAK to PDX, most of the route. Its 78.9% on time is about level with the route as a whole at 79.6%. 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 78.9%. 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.

On-time performance by carrier on OAK to PDX
AirlineFlightsOn timeAvg delayCancelledGrade
Alaska Airlinesthin sample16100.0%0.00%A+
SkyWest Airlinesthin sample10084.0%45 min0.00%B+
Southwest Airlines (this page)1,18178.9%54 min0.42%B+

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 36 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am215 flights97.2%
  • 8am–11am181 flights93.3%
  • 11am–2pm160 flights79.4%
  • 2pm–5pm149 flights71.8%
  • 5pm–8pm226 flights73.9%
  • 8pm–5am250 flights61.6%

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 61.6% on time, against 97.2% 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 8pm–5am window is the busiest, with 250 flights scheduled in it.

Across the year

Southwest on OAK to PDX through the year

On-time rate by calendar month94J93F82M78A72M58J71J83A87S80O84N70D
Darker means more delays. Figures are on-time percentages.January best, June worst

June is the worst month at 58.1% on time, 36 points below January, the best at 93.8%. 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. July was the busiest month here, with 119 flights.

Across the week, Tuesday is the strongest day at 88.0% on time and Sunday the weakest at 69.6%. 18 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week74.7Mon88.0Tue87.1Wed74.4Thu73.8Fri87.8Sat69.6Sun
Monday: 74.7 percent on time. Tuesday: 88.0 percent on time. Wednesday: 87.1 percent on time. Thursday: 74.4 percent on time. Friday: 73.8 percent on time. Saturday: 87.8 percent on time. Sunday: 69.6 percent on time

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 68% of the 13,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

  • Late-arriving aircraft
    68%
  • Carrier
    30%
  • National Airspace System
    3%

68% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 13,000 reported delay minutes here, that single category outweighs weather by 68 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 13,341 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 97.2% on time here.

Cancellations are rare at 0.42%, 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 costs

6.2% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 55 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. 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 sample behind these figures is 1,181 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 OAK to PDX

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 93.8% on time and June 58.1%, a swing of 36 points. If the dates move at all, move them out of June before you think about anything else. 1,176 completed flights over 12 months sit behind that.

Related

Where to go next

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.