Carrier route record
UAORD→SAT
United Airlines · Chicago to San Antonio
- Flights
- 833
- Period
- July 2025 to June 2026
- Share of route
- 42%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on ORD to SAT sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 833 flights, with a median arrival 5 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on ORD to SAT from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.6%
Arrivals under 15 minutes late, of 823 completed flights
Avg delay
74 min
Across delayed arrivals only, not all flights
Cancelled
1.08%
National rate is 1.81%
Whole route
74.5%
Every carrier on ORD to SAT, 1,966 flights
These figures cover 833 flights between July 2025 and June 2026. Beyond the headline rate, 9.5% 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
United against every carrier on ORD to SAT
United flew 833 of the 1,966 flights on ORD to SAT, about 42% of it. Its 75.6% on time is about level with the route as a whole at 74.5%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from Republic at 82.3% to American at 68.7%. Three 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 101 | 82.3% | 62 min | 3.96% | B− |
| SkyWest Airlinesthin sample | 132 | 80.5% | 64 min | 3.03% | B− |
| Envoy Airthin sample | 352 | 76.8% | 57 min | 2.56% | B |
| United Airlines (this page) | 833 | 75.6% | 74 min | 1.08% | B |
| American Airlines | 548 | 68.7% | 74 min | 2.55% | C |
Flight by flight
United flight numbers on ORD to SAT
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 31 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–8am—
- 8am–11am358 flights86.0%
- 11am–2pm112 flights74.1%
- 2pm–5pm10 flights—
- 5pm–8pm88 flights55.3%
- 8pm–5am265 flights69.6%
Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 55.3% on time, against 86.0% for the 8am–11am 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 8am–11am window is the busiest, with 358 flights scheduled in it.
Across the year
United on ORD to SAT through the year
October is the best month on the calendar at 88.0% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. April was the busiest month here, with 86 flights.
Across the week, Tuesday is the strongest day at 82.6% on time and Sunday the weakest at 69.7%. 13 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 50% of the 15,000 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.
- 50%Late-arriving aircraft
- 27%Carrier
- 15%National Airspace System
- 7%Extreme weather
50% 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 15,000 reported delay minutes here, that single category outweighs weather by 7 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 14,916 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 86.0% on time here.
Cancellations sit at 1.08% against a national 1.81%, which is ordinary. Diversions add another 0.12%.
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. 9.5% 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 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 is a different operation and performs like one: it runs 80.1% on time across 833 flights, 5 points above 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 5 points of difference.
One caution: this is a thin sample. 833 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 United on ORD to SAT
Put together: treat all of this as provisional. 833 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 75.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 823 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to SAT, every carrier
- United on SAT to ORD, the return leg
- Republic Airways on ORD to SAT82.3%
- SkyWest Airlines on ORD to SAT80.5%
- Envoy Air on ORD to SAT76.8%
- American Airlines on ORD to SAT68.7%
- United Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- San Antonio International (SAT) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.