Airline on-time record

UA

United Airlines

Flights: 814,574
Period: June 2025 to May 2026
Airports: 25
US rank: #5 by volume

United Airlines lands a B, 2 points better than the national rate of 77.4%. About one flight in five arrive 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 814,574 flights, of which Cleveland (CLE) flew 8,816 at 84.9% on time.

Cleveland (CLE) is the most reliable of the 25 airports covered here at 84.9% on time across 8,816 flights.

On time

78.9%

National average is 77.4%

Avg delay

72 min

Across delayed flights only

Cancelled

1.01%

National rate is 1.80%

Largest base

DEN

106,792 departures, 78.2% on time

These figures cover 815,000 flights between June 2025 and May 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.

Airport by airport

Where United Airlines runs well, and where it does not

The choice of airport is not cosmetic here. Cleveland (CLE) arrives on time 84.9% of the time; New York (LGA) manages 71.8%. Sample sizes sit next to every figure, because a two-point gap across 9,051 flights means less than a ten-point one.

United Airlines on-time performance by departure airport
Airport	Flights	On time	Avg delay	Cancelled	Grade
DEN · Denver	106,792	78.2%	65 min	0.48%	B+
ORD · Chicago	98,675	73.2%	70 min	1.14%	C
IAH · Houston	73,829	79.3%	67 min	0.80%	B+
EWR · Newark	67,201	76.6%	76 min	2.04%	B
SFO · San Francisco	59,976	81.7%	59 min	0.56%	B+
IAD · Washington	36,433	81.7%	74 min	0.78%	B+
LAX · Los Angeles	28,958	83.2%	64 min	0.59%	B+
LAS · Las Vegas	15,192	81.1%	67 min	0.68%	B+
MCO · Orlando	15,037	80.7%	89 min	1.00%	B
BOS · Boston	12,811	78.6%	76 min	1.85%	B
AUS · Austin	10,776	79.4%	75 min	1.25%	B
SAN · San Diego	10,464	81.4%	69 min	0.75%	B+
PHX · Phoenix	10,185	81.5%	77 min	0.79%	B+
DFW · Dallas-Fort Worth	9,723	75.9%	87 min	1.76%	B
LGA · New York	9,051	71.8%	85 min	2.74%	C
FLL · Fort Lauderdale	8,844	82.1%	82 min	1.12%	B
CLE · Cleveland	8,816	84.9%	77 min	0.84%	B+
SEA · Seattle	8,807	80.7%	76 min	0.82%	B+
TPA · Tampa	8,798	80.8%	75 min	0.84%	B+
ATL · Atlanta	7,431	80.3%	83 min	1.44%	B
DCA · Washington	6,888	77.6%	88 min	1.52%	B
MIA · Miami	6,812	77.8%	84 min	1.01%	B
MSY · New Orleans	6,808	83.7%	76 min	0.82%	B+
BNA · Nashville	6,670	76.9%	85 min	1.41%	B
PDX · Portland	6,521	82.3%	65 min	0.67%	B+

The spread between CLE and LGA is 13 points, wide enough that it should decide the booking. On a hundred trips that is 13 more arrivals inside the on-time window.

Route by route

Busiest United Airlines routes

These are the 25 routes United Airlines flies most often, each against its network-wide 78.9%. Route-level variation inside a single airline is routinely wider than the gap between two airlines nationally.

Busiest United Airlines routes by flight volume
Route	Flights	On time	Avg delay	Cancelled	Grade
LGA to ORD	4,658	67.0%	87 min	3.50%	C−
ORD to LGA	4,658	67.6%	81 min	3.16%	C−
ORD to EWR	4,335	70.9%	88 min	2.19%	C
EWR to ORD	4,330	71.1%	75 min	2.12%	C
IAH to ORD	3,981	78.2%	66 min	0.73%	B+
MCO to EWR	3,979	77.7%	102 min	1.96%	B
EWR to MCO	3,979	78.5%	77 min	1.81%	B
ORD to IAH	3,973	78.3%	67 min	0.73%	B+
IAH to DEN	3,854	81.2%	70 min	0.31%	B+
DEN to IAH	3,854	77.7%	65 min	0.34%	B+
SFO to ORD	3,774	78.8%	68 min	1.01%	B
ORD to SFO	3,772	72.1%	72 min	1.03%	C
EWR to SFO	3,753	70.5%	95 min	2.66%	C
SFO to EWR	3,750	74.1%	82 min	2.40%	C
ORD to DEN	3,701	77.6%	71 min	0.92%	B+
DEN to ORD	3,701	71.3%	75 min	0.73%	C+
SFO to IAH	3,596	84.5%	53 min	0.36%	B+
IAH to SFO	3,595	79.2%	71 min	0.53%	B+
LAX to EWR	3,530	78.3%	79 min	2.04%	B
EWR to LAX	3,530	72.3%	83 min	2.12%	C
IAH to EWR	3,473	74.0%	75 min	1.58%	C
EWR to IAH	3,469	79.4%	76 min	1.70%	B
ORD to LAX	3,396	77.5%	68 min	0.62%	B+
IAH to LAX	3,394	83.7%	63 min	0.41%	B+
LAX to IAH	3,394	86.7%	57 min	0.35%	A+

Departure window

The best time of day to fly United Airlines

Departure time matters more here than the choice of airport. The gap between the best and worst window is 21 points, against 13 points between the best and worst airport. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am126,319 flights89.7%
8am–11am166,345 flights84.9%
11am–2pm145,446 flights80.9%
2pm–5pm141,842 flights73.3%
5pm–8pm145,966 flights68.8%
8pm–5am88,656 flights74.6%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 89.7% of the time, against 68.8% for the evening window. That is 21 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on.

Across the year

United Airlines through the calendar

United's year swings by 15 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.

Darker means more delays. Figures are on-time percentages.February best, July worst

July is the worst month at 69.6% on time, 15 points below February, the best at 84.2%. 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.

Across the week, Tuesday is the strongest day at 82.1% on time and Sunday the weakest at 75.9%. 6 points is a smaller lever than departure hour, but it is free.

Delay causes

What holds United Airlines up

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 12.2 million reported delay minutes.

Late-arriving aircraft
37%
National Airspace System
33%
Carrier
26%
Extreme weather
5%
Security
0%

37% 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 12.2 million reported delay minutes here, that single category outweighs weather by 8 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.

33% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No airport can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 4.02 million minutes out of 12.2 million, against a national NAS share of 21%.

Cancellations sit at 1.01% against a national 1.80%, which is ordinary. Diversions add another 0.30%.

7.7% of arrivals land an hour or more late, close to the national 8.2%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route are the a little over an hour kind, which a normal layover absorbs.

814,574 flights sit behind these numbers, which is a large enough sample that the headline rate is not moving on noise. Where a sub-group falls below 30 flights the site shows a dash instead of a percentage.

What to do with this

Booking United Airlines

Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 84.2% on time and July 69.6%, a swing of 15 points. If the dates move at all, move them out of July before you think about anything else.

Common questions

United Airlines reliability questions

How often is United Airlines delayed?

About one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.1% of the 814,574 flights in this analysis, against 22.6% nationally. Delayed flights are late by a little over an hour on average.

Which airport does United Airlines run best from?

Cleveland (CLE) leads at 84.9% on time across 8,816 flights. New York (LGA) is at the other end on 71.8%, a gap of 13 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on United Airlines?

The 5am–8am departure window is the strongest at 89.7% on time. The 5pm–8pm window is the weakest at 68.8%, 21 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are July delays on United Airlines?

July is the weakest month at 69.6% on time, compared with 84.2% in February. Across the year that is 15 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, June 2025 to May 2026. Updated monthly. How this data is collected.

Key figures