Route reliability record
SAT→ORD
San Antonio to Chicago
- Flights
- 1,968
- Period
- July 2025 to June 2026
- Distance
- 1,041 mi
- Carriers
- 5
This route lands a B, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 1,968 SAT to ORD flights, of which United Airlines flew 833 at 80.1% on time.
Best time to fly SAT to ORD: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 86.2% of the time and Tuesday flights 81.1%, against 76.3% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.3%
Arrivals under 15 minutes late, of 1,908 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
2.29%
National rate is 1.81%
Best carrier
United
80.1% on time across 833 flights
These figures cover 1,968 flights between July 2025 and June 2026. Beyond the headline rate, 8.8% 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
Which airline is most reliable on SAT to ORD
The choice of carrier is not cosmetic here. United Airlines arrives on time 80.1% of the time; American Airlines manages 73.1%. Sample sizes sit next to every figure, because a two-point gap across 550 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 833 | 80.1% | 87 min | 1.20% | B |
| Envoy Airthin sample | 352 | 76.6% | 67 min | 2.84% | B |
| Republic Airwaysthin sample | 101 | 74.7% | 54 min | 4.95% | C− |
| American Airlines | 550 | 73.1% | 74 min | 2.55% | C |
| SkyWest Airlinesthin sample | 132 | 65.9% | 61 min | 4.55% | 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
Flights on SAT to ORD
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Best ways to make this trip
The most reliable ways to fly San Antonio to Chicago
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SAT → ORDSan Antonio to Chicago | United Airlines | 79.1% | 80.1% | 1.20% | 5am–8am, Tue | UA 1332 07:00 |
| 2. SAT → ORDSan Antonio to Chicago | American Airlines | 71.2% | 73.1% | 2.55% | 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.
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 23 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am711 flights86.2%
- 8am–11am18 flights—
- 11am–2pm409 flights77.7%
- 2pm–5pm283 flights74.5%
- 5pm–8pm544 flights63.2%
- 8pm–5am3 flights—
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 63.2% on time, against 86.2% 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 711 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 19 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.
Delays peak in March, when the on-time rate falls to 65.9%. February is the strongest month at 84.8%. Moving a flexible trip across that boundary buys 19 points. March was the busiest month here, with 179 flights.
Across the week, Tuesday is the strongest day at 81.1% on time and Sunday the weakest at 73.6%. 8 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 34,000 reported delay minutes.
- 41%Late-arriving aircraft
- 29%National Airspace System
- 23%Carrier
- 7%Extreme weather
- 0%Security
41% 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 34,000 reported delay minutes here, that single category outweighs weather by 6 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 33,799 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 86.2% on time here.
Cancellations sit at 2.29% against a national 1.81%, which is ordinary. Diversions add another 0.76%.
Connections and stage length
What a delay here actually costs
8.8% 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 a little over an hour, which a normal layover absorbs.
The 1,041 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 74.5% on time across 1,966 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.
The sample behind these figures is 1,968 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 ORD 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. February runs 84.8% on time and March 65.9%, a swing of 19 points. If the dates move at all, move them out of March before you think about anything else. 1,908 completed flights over 12 months sit behind that.
Common questions
SAT to ORD questions
How often is SAT to ORD delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.7% of the 1,968 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on SAT to ORD?
United Airlines leads at 80.1% on time across 833 flights. American Airlines is at the other end on 73.1%, a gap of 7 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 SAT to ORD?
The 5am–8am departure window is the strongest at 86.2% on time. The 5pm–8pm window is the weakest at 63.2%, 23 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 March delays on SAT to ORD?
March is the weakest month at 65.9% on time, compared with 84.8% in February. Across the year that is 19 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
- ORD to SAT — the return legseparate record
- San Antonio International (SAT) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- United Airlines on SAT to ORD80.1%
- Envoy Air on SAT to ORD76.6%
- Republic Airways on SAT to ORD74.7%
- American Airlines on SAT to ORD73.1%
- SkyWest Airlines on SAT to ORD65.9%
- SAT to DFW, a related route77.1%
- LGA to ORD, a related route67.3%
- SAT to DEN, a related route81.0%
- United Airlines on-time record80.1%
- Envoy Air on-time record76.6%
- Republic Airways on-time record74.7%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. SAT to ORD and ORD to SAT 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.