Carrier route record

UADTW→IAH

United Airlines · Detroit to Houston

Flights: 281
Period: July 2025 to June 2026
Share of route: 13%
Carriers: 5

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

United on DTW 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 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 281 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,322 at 79.8% on time.

Set against the rest of the country, United's DTW to IAH record is 9 points better than the US average of 77.6%. That gap is worth roughly 94 fewer late arrivals for every thousand flights.

On time

87.0%

Arrivals under 15 minutes late, of 277 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

1.42%

National rate is 1.81%

Whole route

79.7%

Every carrier on DTW to IAH, 2,129 flights

These figures cover 281 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 DTW to IAH

United flew 281 of the 2,129 flights on DTW to IAH, about 13% of it. Its 87.0% on time is 7 points better than the route as a whole, which runs 79.7%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from United at 87.0% to Frontier at 65.5%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The two carriers here are closely matched: about a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on DTW to IAH
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines (this page)thin sample	281	87.0%	53 min	1.42%	A
Delta Air Lines	1,322	79.8%	55 min	0.83%	B+
Spirit Airlines	403	78.5%	85 min	1.74%	B
SkyWest Airlinesthin sample	3	66.7%	19 min	0.00%	C+
Frontier Airlinesthin sample	120	65.5%	73 min	0.83%	C+

No carrier stands out. Delta tops the table at 79.8%, about a point clear of the bottom, which is inside the range this kind of sample moves year to year.

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 281 flights.

5am–8am104 flights81.6%
8am–11am177 flights90.2%
11am–2pm—
2pm–5pm—
5pm–8pm—
8pm–5am—

Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 90.2% of the time, against 81.6% for the early 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 177 flights scheduled in it.

Across the year

United on DTW to IAH through the year

Jul–Sep 202586 flights90.4%
Oct–Dec 202552 flights80.8%
Jan–Mar 202652 flights86.3%
Apr–Jun 202691 flights87.9%

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 87.0% on time across 281 flights.

Quarter by quarter United on DTW to IAH held fairly steady: 90.4% in Jul–Sep 2025, 80.8% in Oct–Dec 2025, 86.3% in Jan–Mar 2026 and 87.9% in Apr–Jun 2026. A spread of 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Thursday is the strongest day at 95.0% on time and Saturday the weakest at 82.1%. 13 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 51% of the 1,917 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
51%
National Airspace System
33%
Late-arriving aircraft
16%

The largest share of delay minutes, 51%, 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 972 of the 1,917 delay minutes reported here. The split is drawn from 1,917 reported delay minutes.

33% 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 641 minutes out of 1,917, against a national NAS share of 21%.

Cancellations sit at 1.42% 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 1.8% 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.

The 1,075 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 is a different operation and performs like one: it runs 70.3% on time across 283 flights, 17 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 17 points of difference.

One caution: this is a thin sample. 281 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 DTW to IAH

Put together: treat all of this as provisional. 281 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 87.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 277 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