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DelayAtlas

Route reliability record

SJCPDX

San Jose to Portland

Flights
1,621
Period
July 2025 to June 2026
Distance
569 mi
Carriers
3
B+GRADE

This route earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 1,621 SJC to PDX flights, of which SkyWest Airlines flew 484 at 93.0% on time.

Best time to fly SJC to PDX: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 96.3% of the time and Wednesday flights 91.5%, against 84.9% for the route overall.

Set against the rest of the country, this route's record is 7 points better than the US average of 77.6%. That gap is worth roughly 73 fewer late arrivals for every thousand flights.

Key figures

On time

84.9%

Arrivals under 15 minutes late, of 1,620 completed flights

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

Best carrier

SkyWest

93.0% on time across 484 flights

These figures cover 1,621 flights between July 2025 and June 2026. The median arrival is 9 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

Which airline is most reliable on SJC to PDX

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 93.0% of the time; Southwest Airlines manages 79.1%. Sample sizes sit next to every figure, because a two-point gap across 973 flights means less than a ten-point one.

On-time performance by carrier on SJC to PDX
AirlineFlightsOn timeAvg delayCancelledGrade
Alaska Airlinesthin sample16495.1%101 min0.00%A+
SkyWest Airlines48493.0%66 min0.00%A+
Southwest Airlines97379.1%50 min0.00%B+

The spread between SkyWest and Southwest is 14 points, wide enough that it should decide the booking. On a hundred trips that is 14 more arrivals inside the on-time window.

Best ways to make this trip

The most reliable ways to fly San Jose to Portland

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.

Most reliable ways to fly from SJC to PDX
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. SJCPDXSan Jose to PortlandSkyWest Airlines93.0%93.0%0.00%2pm–5pm, Wed
2. SFOPDXSan Francisco to PortlandUnited Airlines81.0%81.1%0.18%5am–8am, Sat
3. SFOPDXSan Francisco to PortlandAlaska Airlines79.8%80.2%0.51%5am–8am, SatAS 1410 08:00
4. SJCPDXSan Jose to PortlandSouthwest Airlines79.1%79.1%0.00%5am–8am, Wed
5. OAKPDXOakland to PortlandSouthwest Airlines78.6%78.9%0.42%5am–8am, Tue

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.

Plan this trip by month, day and time

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 30 points, against 14 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am242 flights96.3%
  • 8am–11am262 flights94.3%
  • 11am–2pm462 flights91.1%
  • 2pm–5pm205 flights72.2%
  • 5pm–8pm242 flights78.5%
  • 8pm–5am208 flights65.9%

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

Book the early departure. Flights leaving between 5am–8am arrive on time 96.3% of the time, against 65.9% for the overnight window. That is 30 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 462 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 16 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.

On-time rate by calendar month89J89F89M90A91M80J75J85A83S81O84N87D
Darker means more delays. Figures are on-time percentages.May best, July worst

July is the worst month at 75.0% on time, 16 points below May, the best at 90.5%. 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. December was the busiest month here, with 184 flights.

Across the week, Wednesday is the strongest day at 91.5% on time and Friday the weakest at 79.2%. 12 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week85.3Mon90.0Tue91.5Wed82.9Thu79.2Fri86.0Sat80.4Sun
Monday: 85.3 percent on time. Tuesday: 90.0 percent on time. Wednesday: 91.5 percent on time. Thursday: 82.9 percent on time. Friday: 79.2 percent on time. Saturday: 86.0 percent on time. Sunday: 80.4 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 69% 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
    69%
  • Carrier
    27%
  • National Airspace System
    4%
  • Extreme weather
    1%

69% 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 69 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 13,194 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 96.3% on time here.

Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are 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 4.1% 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 569 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 runs 82.3% on time across 1,636 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,621 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 PDX 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. May runs 90.5% on time and July 75.0%, a swing of 16 points. If the dates move at all, move them out of July before you think about anything else. 1,620 completed flights over 12 months sit behind that.

Common questions

SJC to PDX questions

How often is SJC to PDX delayed?

About one flight in seven arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 15.1% of the 1,621 flights in this analysis, against 22.4% nationally. Delayed flights are late by roughly 55 minutes on average.

Which airline is most reliable on SJC to PDX?

SkyWest Airlines leads at 93.0% on time across 484 flights. Southwest Airlines is at the other end on 79.1%, a gap of 14 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 SJC to PDX?

The 5am–8am departure window is the strongest at 96.3% on time. The 8pm–5am window is the weakest at 65.9%, 30 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 SJC to PDX?

July is the weakest month at 75.0% on time, compared with 90.5% in May. Across the year that is 16 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

Direction matters. SJC to PDX and PDX to SJC 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.