Carrier route record
UAIAH→RDU
United Airlines · Houston to Raleigh
- 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 IAH to RDU earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 696 flights, with a median arrival 6 minutes early.
Set against the rest of the country, United's IAH to RDU record is 7 points better than the US average of 77.3%. That gap is worth roughly 73 fewer late arrivals for every thousand flights.
Key figures
On time
84.6%
Arrivals under 15 minutes late, of 689 completed flights
Avg delay
61 min
Across delayed arrivals only, not all flights
Cancelled
0.86%
National rate is 1.89%
Whole route
83.2%
Every carrier on IAH to RDU, 943 flights
These figures cover 696 flights between September 2025 and August 2026. The median arrival is 6 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 IAH to RDU
United flew 696 of the 943 flights on IAH to RDU, most of the route. Its 84.6% on time is about level with the route as a whole at 83.2%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from United at 84.6% to SkyWest at 0.0%. 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 |
|---|---|---|---|---|---|
| United Airlines (this page) | 696 | 84.6% | 61 min | 0.86% | B+ |
| Frontier Airlinesthin sample | 246 | 79.4% | 82 min | 2.44% | B |
| SkyWest Airlinesthin sample | 1 | 0.0% | 22 min | 0.00% | F+ |
Flight by flight
United flight numbers on IAH to RDU
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 15 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am27 flights—
- 11am–2pm316 flights92.3%
- 2pm–5pm1 flights—
- 5pm–8pm352 flights77.4%
- 8pm–5am—
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 92.3% on time, ahead of 5pm–8pm at 77.4%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 5pm–8pm window is the busiest, with 352 flights scheduled in it.
Across the year
United on IAH to RDU through the year
June is the worst month at 62.9% on time, 35 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, Wednesday is the strongest day at 91.2% on time and Monday the weakest at 79.8%, a spread of 11 points.
Arrival by arrival
How late United on IAH to RDU runs when it is late
The 106 late arrivals split 32 under half an hour, 39 between 30 and 60 minutes, and 35 an hour or more.
- 15+ min early152 flights22.1%
- Within 15 min431 flights62.6%
- 15–29 min late32 flights4.6%
- 30–59 min late39 flights5.7%
- 1–2 hours late24 flights3.5%
- 2+ hours late11 flights1.6%
Scale runs 0% to 100%.
Share of 689 completed flights by arrival against schedule.
23 of 113 late departures made up the time and arrived on time, 20% of them. 16 flights left on time and still arrived late.
The worst days
Worst days for United on IAH to RDU
The latest arrival of the period was on 16 March 2026, 4 hours 31 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 16 March 2026 | 4 hours 31 minutes | Late-arriving aircraft |
| 22 June 2026 | 4 hours 14 minutes | Late-arriving aircraft |
| 12 April 2026 | 3 hours 24 minutes | Late-arriving aircraft |
| 15 June 2026 | 3 hours 7 minutes | Late-arriving aircraft |
| 28 August 2026 | 3 hours | Late-arriving aircraft |
Delay causes
Why United runs late on this route
Late-arriving aircraft accounts for 51% of the 6,421 delay minutes carriers reported here, and the remaining four split what is left.
- 51%Late-arriving aircraft
- 35%Carrier
- 10%National Airspace System
- 3%Extreme weather
51% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 6,421 reported delay minutes here, that single category outweighs weather by 15 to one. The split is drawn from 6,421 reported delay minutes.
The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,264 of the 6,421 delay minutes reported here.
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
5.1% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 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.
The return leg is a different operation and performs like one: it runs 89.1% on time across 696 flights, 5 points above 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 IAH to RDU
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 84.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 689 completed flights over 12 months sit behind that.
Related
Where to go next
- IAH to RDU, every carrier
- United on RDU to IAH, the return leg
- Frontier Airlines on IAH to RDU79.4%
- United Airlines network-wide record
- George Bush Intercontinental (IAH) delay statistics
- Raleigh-Durham International (RDU) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
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.