Carrier route record

UAIAD→CMH

United Airlines · Washington to Columbus

Flights: 389
Period: July 2025 to June 2026
Share of route: 37%
Carriers: 2

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

United on IAD to CMH 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 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 389 flights, with a median arrival 8 minutes early.

Set against the rest of the country, United's IAD to CMH record is 7 points better than the US average of 77.6%. That gap is worth roughly 74 fewer late arrivals for every thousand flights.

On time

85.0%

Arrivals under 15 minutes late, of 387 completed flights

Avg delay

64 min

Across delayed arrivals only, not all flights

Cancelled

0.26%

National rate is 1.81%

Whole route

82.1%

Every carrier on IAD to CMH, 1,061 flights

These figures cover 389 flights between July 2025 and June 2026. The median arrival is 8 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 IAD to CMH

United flew 389 of the 1,061 flights on IAD to CMH, about 37% of it. Its 85.0% on time is 3 points better than the route as a whole, which runs 82.1%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 85.0% to Republic at 80.4%.

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 IAD to CMH
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines (this page)	389	85.0%	64 min	0.26%	A+
Republic Airways	672	80.4%	84 min	2.08%	B

Departure window

When United runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 389 flights.

5am–8am—
8am–11am157 flights88.5%
11am–2pm93 flights88.2%
2pm–5pm—
5pm–8pm138 flights79.6%
8pm–5am1 flights—

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 88.5% of the time, against 79.6% for the evening window. That is 9 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 157 flights scheduled in it.

Across the year

United on IAD to CMH through the year

Jul–Sep 202591 flights91.2%
Oct–Dec 202575 flights85.3%
Jan–Mar 2026131 flights76.0%
Apr–Jun 202692 flights91.3%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 85.0% on time across 389 flights.

United on IAD to CMH did not run the same all year. Its best quarter was Apr–Jun 2026 at 91.3% on time and its weakest Jan–Mar 2026 at 76.0%, a swing of 15 points on roughly 97 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Across the week, Wednesday is the strongest day at 92.2% on time and Sunday the weakest at 75.9%. 16 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. Carrier accounts for 48% of the 3,736 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.

Carrier
48%
Late-arriving aircraft
28%
National Airspace System
17%
Extreme weather
7%

The largest share of delay minutes, 48%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 1,780 of the 3,736 delay minutes reported here. The split is drawn from 3,736 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 88.5% on time here.

Cancellations are rare at 0.26%, 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

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 299 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 is a different operation and performs like one: it runs 79.7% on time across 388 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. 389 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 IAD to CMH

Put together: treat all of this as provisional. 389 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 85.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 387 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