Airline on-time record

UA

United Airlines

Flights: 821,041
Period: July 2025 to June 2026
Airports: 25
US rank: #5 by volume

United Airlines lands a B, about a point better than the national rate of 77.6%. 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 821,041 flights, of which Cleveland (CLE) flew 8,857 at 84.7% on time.

Cleveland (CLE) is the most reliable of the 25 airports covered here at 84.7% on time across 8,857 flights.

On time

79.0%

National average is 77.6%

Avg delay

72 min

Across delayed flights only

Cancelled

1.01%

National rate is 1.81%

Largest base

DEN

107,305 departures, 78.4% on time

These figures cover 821,000 flights between July 2025 and June 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 84.7% of the time; New York (LGA) manages 71.9%. Sample sizes sit next to every figure, because a two-point gap across 9,061 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	107,305	78.4%	64 min	0.46%	B+
ORD · Chicago	99,843	73.1%	71 min	1.23%	C
IAH · Houston	74,010	79.6%	65 min	0.67%	B+
EWR · Newark	68,031	76.9%	75 min	2.01%	B
SFO · San Francisco	60,681	81.1%	59 min	0.55%	B+
IAD · Washington	36,559	82.3%	73 min	0.80%	B+
LAX · Los Angeles	29,181	83.1%	64 min	0.58%	B+
LAS · Las Vegas	15,170	80.7%	67 min	0.66%	B+
MCO · Orlando	15,061	81.1%	88 min	0.98%	B+
BOS · Boston	12,917	78.6%	76 min	1.90%	B
AUS · Austin	10,844	79.7%	74 min	1.18%	B
SAN · San Diego	10,504	81.3%	69 min	0.75%	B+
PHX · Phoenix	10,125	81.3%	76 min	0.76%	B+
DFW · Dallas-Fort Worth	9,850	75.9%	88 min	1.72%	B
LGA · New York	9,061	71.9%	85 min	2.80%	C
FLL · Fort Lauderdale	8,891	82.4%	83 min	1.09%	B
CLE · Cleveland	8,857	84.7%	78 min	0.84%	B+
SEA · Seattle	8,804	80.2%	76 min	0.80%	B+
TPA · Tampa	8,735	81.4%	75 min	0.82%	B+
ATL · Atlanta	7,532	80.3%	83 min	1.47%	B
DCA · Washington	6,900	77.8%	89 min	1.55%	B
MIA · Miami	6,839	77.9%	83 min	1.01%	B
MSY · New Orleans	6,803	83.9%	74 min	0.73%	B+
BNA · Nashville	6,723	77.0%	83 min	1.43%	B
PDX · Portland	6,566	81.8%	66 min	0.62%	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 79.0%. 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
ORD to LGA	4,662	67.4%	81 min	3.41%	C−
LGA to ORD	4,662	66.7%	88 min	3.69%	C−
ORD to EWR	4,391	71.3%	86 min	2.37%	C
EWR to ORD	4,389	71.1%	76 min	2.26%	C
EWR to MCO	4,014	79.4%	76 min	1.82%	B
MCO to EWR	4,014	78.1%	103 min	1.97%	B
IAH to ORD	4,007	78.2%	70 min	0.60%	B+
ORD to IAH	4,000	78.6%	67 min	0.65%	B+
IAH to DEN	3,875	81.5%	69 min	0.21%	B+
DEN to IAH	3,875	78.0%	62 min	0.23%	B+
SFO to ORD	3,815	78.3%	71 min	1.02%	B
ORD to SFO	3,813	69.8%	73 min	1.05%	C
EWR to SFO	3,793	68.9%	92 min	2.53%	C
SFO to EWR	3,790	74.8%	82 min	2.24%	C
ORD to DEN	3,758	77.4%	73 min	0.93%	B+
DEN to ORD	3,756	71.4%	79 min	0.75%	C+
IAH to SFO	3,600	78.6%	66 min	0.47%	B+
SFO to IAH	3,600	84.8%	53 min	0.28%	B+
EWR to LAX	3,540	72.2%	83 min	1.95%	C
LAX to EWR	3,539	78.7%	79 min	1.92%	B
EWR to IAH	3,534	80.4%	74 min	1.64%	B
IAH to EWR	3,534	74.5%	72 min	1.56%	C
IAH to LAX	3,416	84.4%	59 min	0.32%	B+
LAX to IAH	3,415	87.1%	55 min	0.26%	A+
ORD to DCA	3,393	70.6%	75 min	1.80%	C

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–8am127,814 flights89.6%
8am–11am167,412 flights84.8%
11am–2pm147,029 flights80.9%
2pm–5pm142,943 flights73.4%
5pm–8pm146,925 flights69.0%
8pm–5am88,918 flights74.9%

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 89.6% of the time, against 69.0% 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. The 8am–11am window is the busiest, with 167,412 flights scheduled in it.

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. May was the busiest month here, with 74,200 flights.

Across the week, Tuesday is the strongest day at 82.6% on time and Sunday the weakest at 75.8%. 7 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 12.3 million reported delay minutes.

Late-arriving aircraft
37%
National Airspace System
33%
Carrier
25%
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 12.3 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. The split is drawn from 12,285,235 reported delay minutes.

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 4.10 million minutes out of 12.3 million, against a national NAS share of 21%.

Cancellations sit at 1.01% against a national 1.81%, which is ordinary. Diversions add another 0.30%.

7.7% of arrivals land an hour or more late, close to the national 8.1%. 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.

821,041 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. 810,339 completed flights over 12 months sit behind that.

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 21.0% of the 821,041 flights in this analysis, against 22.4% 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 84.7% on time across 8,857 flights. New York (LGA) is at the other end on 71.9%, 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 89.6% on time. The 5pm–8pm window is the weakest at 69.0%, 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, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures