Route reliability record
RDU→ORD
Raleigh to Chicago
- Flights
- 3,740
- Period
- September 2025 to August 2026
- Distance
- 646 mi
- Carriers
- 7
This route 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 77.3%. The late ones land close to two hours behind schedule. That rests on 3,740 RDU to ORD flights, of which American Airlines flew 518 at 80.6% on time.
Best time to fly RDU to ORD: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 87.4% of the time and Tuesday flights 77.5%, against 74.3% for the route overall.
American Airlines is the most reliable of the four carriers covered here at 80.6% on time across 518 flights.
Key figures
On time
74.3%
Arrivals under 15 minutes late, of 3,619 completed flights
Avg delay
100 min
Across delayed arrivals only, not all flights
Cancelled
2.81%
National rate is 1.89%
Best carrier
American
80.6% on time across 518 flights
These figures cover 3,740 flights between September 2025 and August 2026. Beyond the headline rate, 11.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on RDU to ORD
The choice of carrier is not cosmetic here. American Airlines arrives on time 80.6% of the time; Republic Airways manages 71.6%. Sample sizes sit next to every figure, because a two-point gap across 1,155 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 154 | 81.1% | 195 min | 3.25% | B− |
| American Airlines | 518 | 80.6% | 153 min | 3.28% | B− |
| United Airlines | 1,292 | 75.1% | 94 min | 1.70% | B |
| Envoy Air | 521 | 73.0% | 87 min | 1.92% | C |
| Republic Airways | 1,155 | 71.6% | 80 min | 3.98% | C− |
| Frontier Airlinesthin sample | 98 | 58.1% | 155 min | 5.10% | D− |
| PSA Airlinesthin sample | 2 | 50.0% | 31 min | 0.00% | F+ |
Republic Airways cancels 4.0% 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
Flights on RDU 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.
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Best ways to make this trip
The most reliable ways to fly Raleigh to Chicago
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 1 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. RDU → ORDRaleigh to Chicago | American Airlines | 78.0% | 80.6% | 3.28% | 8am–11am, Fri | — |
| 2. RDU → MDWRaleigh to Chicago | Southwest Airlines | 75.9% | 77.3% | 1.77% | 5am–8am, Wed | — |
| 3. RDU → ORDRaleigh to Chicago | United Airlines | 73.8% | 75.1% | 1.70% | 5am–8am, Tue | UA 1920 13:30 |
| 4. RDU → ORDRaleigh to Chicago | Envoy Air | 71.6% | 73.0% | 1.92% | 5am–8am, Wed | — |
| 5. RDU → ORDRaleigh to Chicago | Republic Airways | 68.8% | 71.6% | 3.98% | 8am–11am, Sat | — |
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 37 points, against 9 points between the best and worst carrier.
- 5am–8am760 flights87.4%
- 8am–11am768 flights86.3%
- 11am–2pm766 flights79.2%
- 2pm–5pm614 flights65.9%
- 5pm–8pm765 flights52.5%
- 8pm–5am67 flights50.8%
Scale runs 40% to 95%.
The 8pm–5am window is where this operation falls apart: 50.8% on time, against 87.4% 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 768 flights scheduled in it.
Explore
Filter RDU to ORD by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On RDU to ORD, the best departure window is 5am–8am at 87.4% on time and the worst is 8pm–5am at 50.8%, a wide gap of 36.6 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am87.4%
- 8–11am86.3%
- 11am–2pm79.2%
- 2–5pm65.9%
- 5–8pm52.5%
- 8pm–5am50.8%
best all US flightsScale 40% to 95%.
Across the year
When delays peak on this route
This route's year swings by 14 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.
September is the best month on the calendar at 82.7% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. May was the busiest month here, with 374 flights.
Across the week, Tuesday is the strongest day at 77.5% on time and Sunday the weakest at 70.6%, a spread of 7 points.
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 93,000 reported delay minutes.
- 35%National Airspace System
- 33%Late-arriving aircraft
- 24%Carrier
- 8%Extreme weather
- 0%Security
35% 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 32,000 minutes out of 93,000, against a national NAS share of 21%. The split is drawn from 93,074 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 87.4% on time here.
Cancellations run at 2.81%, against 1.89% nationally. That is roughly one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
11.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
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.
The return leg runs 72.9% on time across 3,742 flights, within about 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 3,740 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 delay figures matter less here than the 2.81% cancellation rate. A late arrival costs you close to two hours; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 3,619 completed flights over 12 months sit behind that.
Common questions
RDU to ORD questions
How often is RDU 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 25.7% of the 3,740 flights in this analysis, against 22.7% nationally. Delayed flights are late by close to two hours on average.
Which airline is most reliable on RDU to ORD?
American Airlines leads at 80.6% on time across 518 flights. Republic Airways is at the other end on 71.6%, a gap of 9 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 RDU to ORD?
The 5am–8am departure window is the strongest at 87.4% on time. The 8pm–5am window is the weakest at 50.8%, 37 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 RDU to ORD?
March is the weakest month at 69.1% on time, compared with 82.7% in September. Across the year that is 14 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 RDU — the return legseparate record
- Raleigh-Durham International (RDU) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- SkyWest Airlines on RDU to ORD81.1%
- American Airlines on RDU to ORD80.6%
- United Airlines on RDU to ORD75.1%
- Envoy Air on RDU to ORD73.0%
- Republic Airways on RDU to ORD71.6%
- RDU to ATL, a related route86.5%
- LGA to ORD, a related route66.7%
- RDU to CLT, a related route81.9%
- SkyWest Airlines on-time record81.1%
- American Airlines on-time record80.6%
- United Airlines on-time record75.1%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. RDU to ORD and ORD to RDU 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.