Carrier route record

UARDU→IAD

United Airlines · Raleigh to Washington

Flights: 1,080
Period: July 2025 to June 2026
Share of route: 84%
Carriers: 2

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.

United on RDU to IAD 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 10 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 1,080 flights, with a median arrival 10 minutes early.

Set against the rest of the country, United's RDU to IAD record is 10 points better than the US average of 77.6%. That gap is worth roughly 99 fewer late arrivals for every thousand flights.

On time

87.5%

Arrivals under 15 minutes late, of 1,065 completed flights

Avg delay

81 min

Across delayed arrivals only, not all flights

Cancelled

1.39%

National rate is 1.81%

Whole route

86.5%

Every carrier on RDU to IAD, 1,293 flights

These figures cover 1,080 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 IAD

United flew 1,080 of the 1,293 flights on RDU to IAD, most of the route. Its 87.5% on time is about level with the route as a whole at 86.5%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 87.5% to Republic at 81.6%. 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.

On-time performance by carrier on RDU to IAD
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines (this page)	1,080	87.5%	81 min	1.39%	A
Republic Airwaysthin sample	213	81.6%	74 min	0.47%	B+

Flight by flight

United flight numbers on RDU to IAD

UA 246315:0274.7% · 261 flights

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–8am235 flights92.2%
8am–11am361 flights93.3%
11am–2pm23 flights—
2pm–5pm261 flights74.7%
5pm–8pm47 flights85.1%
8pm–5am153 flights86.9%

Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 93.3% of the time, against 74.7% for the afternoon 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 8am–11am window is the busiest, with 361 flights scheduled in it.

Across the year

United on RDU to IAD through the year

Darker means more delays. Figures are on-time percentages.June best, December worst

December is the weak month at 76.5% on time, against 94.9% in June. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. March was the busiest month here, with 115 flights.

Across the week, Saturday is the strongest day at 93.1% on time and Sunday the weakest at 83.0%. 10 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 44% of the 11,000 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.

Late-arriving aircraft
44%
National Airspace System
22%
Carrier
19%
Extreme weather
15%

Extreme weather accounts for 15% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.4 times the usual weather exposure. The split is drawn from 10,710 reported delay minutes.

44% 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 11,000 reported delay minutes here, that single category outweighs weather by 3 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.

Cancellations sit at 1.39% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 4.4% land an hour or more behind schedule, against 8.1% 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.

At 225 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.

The return leg runs 85.1% on time across 1,080 flights, within 2 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. 1,080 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 IAD

Put together: treat all of this as provisional. 1,080 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 87.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,065 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures