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DelayAtlas

Carrier route record

WNAUSORD

Southwest Airlines · Austin to Chicago

Flights
207
Period
July 2025 to June 2026
Share of route
7%
Carriers
6
C+GRADE

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

Southwest on AUS to ORD sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 207 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,470 at 74.9% on time.

The national on-time rate over the same period is 77.6%, so Southwest on AUS to ORD runs 9 points behind the country as a whole. Across a thousand flights that is about 88 extra late arrivals.

Key figures

On time

68.8%

Arrivals under 15 minutes late, of 205 completed flights

Avg delay

56 min

Across delayed arrivals only, not all flights

Cancelled

0.48%

National rate is 1.81%

Whole route

72.1%

Every carrier on AUS to ORD, 3,166 flights

These figures cover 207 flights between July 2025 and June 2026. Beyond the headline rate, 9.8% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Southwest against every carrier on AUS to ORD

Southwest flew 207 of the 3,166 flights on AUS to ORD, about 7% of it. Its 68.8% on time is 3 points worse than the route as a whole, which runs 72.1%. Ranked by on-time rate it is number five of six carriers on the route, where the range runs from United at 74.9% to Frontier at 65.1%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on AUS to ORD
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines1,47074.9%80 min1.02%C
Envoy Airthin sample8672.6%62 min2.33%C
American Airlines1,19069.8%105 min3.11%C−
Republic Airwaysthin sample9569.7%71 min6.32%C−
Southwest Airlines (this page)thin sample20768.8%56 min0.48%C+
Frontier Airlinesthin sample11865.1%141 min5.93%C−

American Airlines cancels 3.1% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

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 20 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am
  • 8am–11am110 flights78.2%
  • 11am–2pm96 flights58.5%
  • 2pm–5pm1 flights
  • 5pm–8pm
  • 8pm–5am

Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.

The weak window here is the middle of the day, not the evening: 11am–2pm runs 58.5% on time against 78.2% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8am–11am window is the busiest, with 110 flights scheduled in it.

Across the year

Southwest on AUS to ORD through the year

  • Jul–Sep 202592 flights65.9%
  • Oct–Dec 202532 flights78.1%
  • Jan–Mar 202627 flights
  • Apr–Jun 202656 flights75.0%

Scale runs 55% to 85%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 68.8% on time across 207 flights.

Southwest on AUS to ORD did not run the same all year. Its best quarter was Oct–Dec 2025 at 78.1% on time and its weakest Jul–Sep 2025 at 65.9%, a swing of 12 points on roughly 69 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Across the week, Monday is the strongest day at 83.3% on time and Wednesday the weakest at 61.3%. 22 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week83.3Mon74.2Tue61.3Wed74.2Thu71.0FriSatSun
Monday: 83.3 percent on time. Tuesday: 74.2 percent on time. Wednesday: 61.3 percent on time. Thursday: 74.2 percent on time. Friday: 71.0 percent on time. Saturday: not enough flights. Sunday: not enough flights

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. National Airspace System accounts for 57% of the 3,574 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
    57%
  • Carrier
    22%
  • Late-arriving aircraft
    19%
  • Extreme weather
    2%

57% 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 2,041 minutes out of 3,574, against a national NAS share of 21%. The split is drawn from 3,574 reported delay minutes.

Cancellations are rare at 0.48%, 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

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.8% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

The 977 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 62.3% on time across 207 flights, 7 points below 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 7 points of difference.

One caution: this is a thin sample. 207 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 Southwest on AUS to ORD

Put together: treat all of this as provisional. 207 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 68.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 205 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.