Carrier route record
UARDU→IAH
United Airlines · Raleigh to Houston
- Flights
- 700
- Period
- July 2025 to June 2026
- Share of route
- 77%
- 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 IAH 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 a little over an hour. That rests on 700 flights, with a median arrival 12 minutes early.
Set against the rest of the country, United's RDU to IAH record is 9 points better than the US average of 77.6%. That gap is worth roughly 90 fewer late arrivals for every thousand flights.
Key figures
On time
86.6%
Arrivals under 15 minutes late, of 694 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
0.86%
National rate is 1.81%
Whole route
83.5%
Every carrier on RDU to IAH, 906 flights
These figures cover 700 flights between July 2025 and June 2026. The median arrival is 12 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 IAH
United flew 700 of the 906 flights on RDU to IAH, most of the route. Its 86.6% on time is 3 points better than the route as a whole, which runs 83.5%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 100.0% to Frontier at 72.5%. Two 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 |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| United Airlines (this page) | 700 | 86.6% | 75 min | 0.86% | A+ |
| Frontier Airlinesthin sample | 205 | 72.5% | 96 min | 2.44% | C |
Flight by flight
United flight numbers on RDU to IAH
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 19 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–8am364 flights91.9%
- 8am–11am—
- 11am–2pm28 flights—
- 2pm–5pm143 flights88.7%
- 5pm–8pm165 flights72.7%
- 8pm–5am—
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 91.9% of the time, against 72.7% for the evening window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 364 flights scheduled in it.
Across the year
United on RDU to IAH through the year
July is the worst month at 62.5% on time, 36 points below January, the best at 98.1%. 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. March was the busiest month here, with 86 flights.
Across the week, Saturday is the strongest day at 89.8% on time and Thursday the weakest at 81.4%. 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. National Airspace System accounts for 45% of the 6,961 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%National Airspace System
- 32%Carrier
- 18%Late-arriving aircraft
- 5%Extreme weather
45% 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 3,106 minutes out of 6,961, against a national NAS share of 21%. The split is drawn from 6,961 reported delay minutes.
Cancellations are rare at 0.86%, 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
5.2% 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 1,042 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 83.9% on time across 700 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. 700 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 IAH
Put together: treat all of this as provisional. 700 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 86.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 694 completed flights over 12 months sit behind that.
Related
Where to go next
- RDU to IAH, every carrier
- United on IAH to RDU, the return leg
- Frontier Airlines on RDU to IAH72.5%
- United Airlines network-wide record
- Raleigh-Durham International (RDU) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.