Carrier route record
UARDU→DEN
United Airlines · Raleigh to Denver
- Flights
- 776
- Period
- July 2025 to June 2026
- Share of route
- 44%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on RDU to DEN earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 776 flights, with a median arrival 10 minutes early.
Set against the rest of the country, United's RDU to DEN record is 9 points better than the US average of 77.6%. That gap is worth roughly 87 fewer late arrivals for every thousand flights.
Key figures
On time
86.3%
Arrivals under 15 minutes late, of 768 completed flights
Avg delay
90 min
Across delayed arrivals only, not all flights
Cancelled
0.64%
National rate is 1.81%
Whole route
80.0%
Every carrier on RDU to DEN, 1,771 flights
These figures cover 776 flights between July 2025 and June 2026. The median arrival is 10 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
United against every carrier on RDU to DEN
United flew 776 of the 1,771 flights on RDU to DEN, about 44% of it. Its 86.3% on time is 6 points better than the route as a whole, which runs 80.0%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from United at 86.3% to Southwest at 74.0%. One 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 |
|---|---|---|---|---|---|
| United Airlines (this page) | 776 | 86.3% | 90 min | 0.64% | A+ |
| Frontier Airlinesthin sample | 286 | 77.5% | 71 min | 1.40% | B |
| Southwest Airlines | 709 | 74.0% | 55 min | 0.85% | C+ |
Flight by flight
United flight numbers on RDU to DEN
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 14 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–8am13 flights—
- 8am–11am350 flights92.8%
- 11am–2pm49 flights91.7%
- 2pm–5pm364 flights79.2%
- 5pm–8pm—
- 8pm–5am—
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 92.8% of the time, against 79.2% for the afternoon window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 364 flights scheduled in it.
Across the year
United on RDU to DEN through the year
July is the worst month at 74.2% on time, 23 points below May, the best at 96.8%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 92 flights.
Across the week, Wednesday is the strongest day at 90.0% on time and Friday the weakest at 82.0%. 8 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 42% of the 9,397 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.
- 42%Late-arriving aircraft
- 28%National Airspace System
- 28%Carrier
- 1%Extreme weather
42% 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 9,397 reported delay minutes here, that single category outweighs weather by 38 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 9,397 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 92.8% on time here.
Cancellations are rare at 0.64%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
6.0% 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 an hour and a half, which a normal layover absorbs.
The 1,436 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 80.9% on time across 775 flights, 5 points below 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. 776 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 RDU to DEN
Put together: treat all of this as provisional. 776 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 86.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 768 completed flights over 12 months sit behind that.
Related
Where to go next
- RDU to DEN, every carrier
- United on DEN to RDU, the return leg
- Frontier Airlines on RDU to DEN77.5%
- Southwest Airlines on RDU to DEN74.0%
- United Airlines network-wide record
- Raleigh-Durham International (RDU) delay statistics
- Denver International (DEN) 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.