Carrier route record
UARDU→IAH
United Airlines · Raleigh to Houston
- Flights
- 696
- Period
- September 2025 to August 2026
- Share of route
- 74%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on RDU to IAH earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 12 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 696 flights, with a median arrival 13 minutes early.
Set against the rest of the country, United's RDU to IAH record is 12 points better than the US average of 77.3%. That gap is worth roughly 118 fewer late arrivals for every thousand flights.
Key figures
On time
89.1%
Arrivals under 15 minutes late, of 690 completed flights
Avg delay
80 min
Across delayed arrivals only, not all flights
Cancelled
0.86%
National rate is 1.89%
Whole route
85.9%
Every carrier on RDU to IAH, 943 flights
These figures cover 696 flights between September 2025 and August 2026. The median arrival is 13 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.
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Carrier by carrier
United against every carrier on RDU to IAH
United flew 696 of the 943 flights on RDU to IAH, most of the route. Its 89.1% on time is 3 points better than the route as a whole, which runs 85.9%. 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 76.8%. 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) | 696 | 89.1% | 80 min | 0.86% | A+ |
| Frontier Airlinesthin sample | 246 | 76.8% | 96 min | 2.03% | B |
Flight by flight
United flight numbers on RDU to IAH
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 11 points, against half a point between the best and worst carrier.
- 5am–8am364 flights92.5%
- 8am–11am—
- 11am–2pm28 flights—
- 2pm–5pm143 flights88.7%
- 5pm–8pm161 flights81.9%
- 8pm–5am—
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 92.5% of the time, against 81.9% for the evening window. That is 11 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
Delays peak in November, when the on-time rate falls to 79.7%. January is the strongest month at 98.1%. Moving a flexible trip across that boundary buys 18 points. March was the busiest month here, with 86 flights.
Across the week, Tuesday is the strongest day at 92.7% on time and Thursday the weakest at 81.4%, a spread of 11 points.
Arrival by arrival
How late United on RDU to IAH runs when it is late
United on RDU to IAH often beats the schedule: 321 of 690 completed flights, 47%, arrived 15 minutes or more early. The 75 late arrivals split 19 under half an hour, 30 between 30 and 60 minutes, and 26 an hour or more.
- 15+ min early321 flights46.5%
- Within 15 min294 flights42.6%
- 15–29 min late19 flights2.8%
- 30–59 min late30 flights4.3%
- 1–2 hours late13 flights1.9%
- 2+ hours late13 flights1.9%
Scale runs 0% to 100%.
Share of 690 completed flights by arrival against schedule.
14 of 65 late departures made up the time and arrived on time, 22% of them. 24 flights left on time and still arrived late.
The worst days
Worst days for United on RDU to IAH
The latest arrival of the period was on 4 July 2026, 10 hours 40 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in March 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 4 July 2026 | 10 hours 40 minutes | Carrier |
| 6 July 2026 | 6 hours 42 minutes | Late-arriving aircraft |
| 16 March 2026 | 5 hours 18 minutes | National Airspace System |
| 1 March 2026 | 4 hours 43 minutes | Carrier |
| 11 March 2026 | 4 hours 8 minutes | National Airspace System |
Delay causes
Why United runs late on this route
National Airspace System accounts for 46% of the 5,963 delay minutes carriers reported here, and the remaining four split what is left.
- 46%National Airspace System
- 33%Carrier
- 17%Late-arriving aircraft
- 4%Extreme weather
46% 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 2,736 minutes out of 5,963, against a national NAS share of 21%. The split is drawn from 5,963 reported delay minutes.
Cancellations are rare at 0.86%, below the national 1.89% 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
Badly late arrivals are rare here: only 3.8% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
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.
The return leg is a different operation and performs like one: it runs 84.6% on time across 696 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. 696 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. 696 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 89.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 690 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 IAH76.8%
- 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 7.05 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.