Carrier route record
UAORD→CHS
United Airlines · Chicago to Charleston
- Flights
- 750
- Period
- July 2025 to June 2026
- Share of route
- 36%
- Carriers
- 6
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on ORD to CHS 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 a little over an hour behind schedule. That rests on 750 flights. The strongest carrier on the route with a full sample, Republic Airways, flew 454 at 81.1% on time.
The US average over the same twelve months is 77.6%, so there is little to separate United on ORD to CHS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.2%
Arrivals under 15 minutes late, of 737 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
1.60%
National rate is 1.81%
Whole route
75.3%
Every carrier on ORD to CHS, 2,091 flights
These figures cover 750 flights between July 2025 and June 2026. Beyond the headline rate, 10.0% 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 CHS
United flew 750 of the 2,091 flights on ORD to CHS, about 36% of it. Its 74.2% on time is about level with the route as a whole at 75.3%. Ranked by on-time rate it is number four of six carriers on the route, where the range runs from PSA at 100.0% to SkyWest at 67.5%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Republic Airways arrives on time 81.1% of the time; Envoy Air manages 74.2%. Sample sizes sit next to every figure, because a two-point gap across 562 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| PSA Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Republic Airways | 454 | 81.1% | 58 min | 1.98% | B |
| Envoy Air | 562 | 74.2% | 50 min | 2.67% | C |
| United Airlines (this page) | 750 | 74.2% | 71 min | 1.60% | C |
| American Airlinesthin sample | 239 | 73.1% | 73 min | 2.09% | C |
| SkyWest Airlinesthin sample | 85 | 67.5% | 71 min | 2.35% | C |
Republic leads Envoy by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
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 32 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am190 flights92.0%
- 8am–11am202 flights75.4%
- 11am–2pm—
- 2pm–5pm148 flights68.7%
- 5pm–8pm194 flights60.3%
- 8pm–5am16 flights—
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 60.3% on time, against 92.0% 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 8am–11am window is the busiest, with 202 flights scheduled in it.
Across the year
United on ORD to CHS through the year
October is the best month on the calendar at 82.4% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. November was the busiest month here, with 90 flights.
Across the week, Tuesday is the strongest day at 79.6% on time and Monday the weakest at 69.7%. 10 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 48% 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.
- 48%Late-arriving aircraft
- 31%Carrier
- 16%National Airspace System
- 5%Extreme weather
48% 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 9 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 13,387 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 92.0% on time here.
Cancellations sit at 1.60% against a national 1.81%, which is ordinary. Diversions add another 0.13%.
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. 10.0% 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 760 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 77.1% on time across 749 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.
One caution: this is a thin sample. 750 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 CHS
Put together: treat all of this as provisional. 750 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 74.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 737 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to CHS, every carrier
- United on CHS to ORD, the return leg
- Republic Airways on ORD to CHS81.1%
- Envoy Air on ORD to CHS74.2%
- American Airlines on ORD to CHS73.1%
- United Airlines network-wide record
- Chicago O'Hare International (ORD) 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.