Carrier route record
UAORD→RDU
United Airlines · Chicago to Raleigh
- Flights
- 1,298
- Period
- July 2025 to June 2026
- Share of route
- 36%
- Carriers
- 7
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on ORD to RDU 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 1,298 flights. The strongest carrier on the route with a full sample, Envoy Air, flew 521 at 77.1% on time.
Envoy Air is the most reliable of the three carriers covered here at 77.1% on time across 521 flights.
Key figures
On time
76.8%
Arrivals under 15 minutes late, of 1,284 completed flights
Avg delay
77 min
Across delayed arrivals only, not all flights
Cancelled
1.00%
National rate is 1.81%
Whole route
73.3%
Every carrier on ORD to RDU, 3,592 flights
These figures cover 1,298 flights between July 2025 and June 2026. Beyond the headline rate, 8.6% 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 RDU
United flew 1,298 of the 3,592 flights on ORD to RDU, about 36% of it. Its 76.8% on time is 4 points better than the route as a whole, which runs 73.3%. Ranked by on-time rate it is number three of seven carriers on the route, where the range runs from SkyWest at 79.1% to PSA at 50.0%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Envoy Air arrives on time 77.1% of the time; American Airlines manages 61.8%. Sample sizes sit next to every figure, because a two-point gap across 555 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 67 | 79.1% | 65 min | 0.00% | B+ |
| Envoy Air | 521 | 77.1% | 54 min | 1.73% | B |
| United Airlines (this page) | 1,298 | 76.8% | 77 min | 1.00% | B |
| Republic Airways | 1,018 | 73.5% | 69 min | 2.85% | C |
| Frontier Airlinesthin sample | 131 | 66.4% | 137 min | 4.58% | C− |
| American Airlines | 555 | 61.8% | 96 min | 3.42% | D− |
| PSA Airlinesthin sample | 2 | 50.0% | 85 min | 0.00% | F+ |
American Airlines cancels 3.4% 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.
Flight by flight
United flight numbers on ORD to RDU
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 22 points, against 15 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am243 flights85.9%
- 8am–11am177 flights81.9%
- 11am–2pm180 flights80.9%
- 2pm–5pm339 flights79.3%
- 5pm–8pm357 flights63.9%
- 8pm–5am2 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: 63.9% on time, against 85.9% 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 5pm–8pm window is the busiest, with 357 flights scheduled in it.
Across the year
United on ORD to RDU through the year
October is the best month on the calendar at 87.4% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. October was the busiest month here, with 120 flights.
Across the week, Tuesday is the strongest day at 82.2% on time and Friday the weakest at 70.9%. 11 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 45% of the 23,000 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.
- 45%Late-arriving aircraft
- 24%Carrier
- 20%National Airspace System
- 12%Extreme weather
Extreme weather accounts for 12% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.9 times the usual weather exposure. The split is drawn from 22,802 reported delay minutes.
45% 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 23,000 reported delay minutes here, that single category outweighs weather by 4 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.
Cancellations sit at 1.00% against a national 1.81%, which is ordinary. Diversions add another 0.08%.
Connections and stage length
What a delay here costs
8.6% 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 646 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 76.3% on time across 1,295 flights, within half a point 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 1,298 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.
What to do with this
Booking United on ORD to RDU
Put together: the calendar is the biggest lever here, not the carrier or the hour. October runs 87.4% on time and March 63.7%, a swing of 24 points. If the dates move at all, move them out of March before you think about anything else. 1,284 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to RDU, every carrier
- United on RDU to ORD, the return leg
- Envoy Air on ORD to RDU77.1%
- Republic Airways on ORD to RDU73.5%
- Frontier Airlines on ORD to RDU66.4%
- American Airlines on ORD to RDU61.8%
- United Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Raleigh-Durham International (RDU) delay statistics
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
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.