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DelayAtlas

Carrier route record

ASPDXORD

Alaska Airlines · Portland to Chicago

Flights
510
Period
July 2025 to June 2026
Share of route
18%
Carriers
3
CGRADE

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

Alaska on PDX to ORD 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 77.6%. The late ones land about 40 minutes behind schedule. That rests on 510 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,393 at 80.7% on time.

The US average over the same twelve months is 77.6%, so there is little to separate Alaska on PDX to ORD from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

74.5%

Arrivals under 15 minutes late, of 502 completed flights

Avg delay

39 min

Across delayed arrivals only, not all flights

Cancelled

1.37%

National rate is 1.81%

Whole route

77.5%

Every carrier on PDX to ORD, 2,766 flights

These figures cover 510 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

Alaska against every carrier on PDX to ORD

Alaska flew 510 of the 2,766 flights on PDX to ORD, about 18% of it. Its 74.5% on time is 3 points worse than the route as a whole, which runs 77.5%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from United at 80.7% to American at 74.0%.

The choice of carrier is not cosmetic here. United Airlines arrives on time 80.7% of the time; American Airlines manages 74.0%. Sample sizes sit next to every figure, because a two-point gap across 863 flights means less than a ten-point one.

On-time performance by carrier on PDX to ORD
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines1,39380.7%68 min0.65%B+
Alaska Airlines (this page)51074.5%39 min1.37%C
American Airlines86374.0%95 min1.51%C

United leads American by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Flight by flight

Alaska flight numbers on PDX to ORD

Departure window

When Alaska runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 20 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am330 flights70.6%
  • 8am–11am21 flights
  • 11am–2pm3 flights
  • 2pm–5pm
  • 5pm–8pm55 flights69.1%
  • 8pm–5am101 flights88.7%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is the strongest at 88.7% on time. The full set of windows spans 20 points.

Across the year

Alaska on PDX to ORD through the year

On-time rate by calendar monthJF90M70A91M78J61J67A74S65O82N74D
Darker means more delays. Figures are on-time percentages.May best, July worst

July is the worst month at 60.7% on time, 30 points below May, the best at 90.6%. 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 61 flights.

Across the week, Thursday is the strongest day at 77.9% on time and Tuesday the weakest at 72.9%. 5 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week74.2Mon72.9Tue73.4Wed77.9Thu75.6Fri73.9Sat73.1Sun
Monday: 74.2 percent on time. Tuesday: 72.9 percent on time. Wednesday: 73.4 percent on time. Thursday: 77.9 percent on time. Friday: 75.6 percent on time. Saturday: 73.9 percent on time. Sunday: 73.1 percent on time

Delay causes

Why Alaska runs late on this route

One category carries most of the weight here. National Airspace System accounts for 68% of the 5,009 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.

  • National Airspace System
    68%
  • Carrier
    27%
  • Late-arriving aircraft
    5%

68% 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 3,414 minutes out of 5,009, against a national NAS share of 21%. The split is drawn from 5,009 reported delay minutes.

Cancellations sit at 1.37% against a national 1.81%, which is ordinary. Diversions add another 0.20%.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 3.8% 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.

At 1,739 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg runs 72.8% on time across 506 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 510 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Alaska on PDX to ORD

Put together: treat all of this as provisional. 510 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 74.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 502 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.