Airline on-time record

UA

United Airlines

Flights: 830,825
Period: September 2025 to August 2026
Airports: 25
US rank: #5 by volume

United Airlines lands a B, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 830,825 flights, of which New Orleans (MSY) flew 6,748 at 84.4% on time.

New Orleans (MSY) is the most reliable of the 25 airports covered here at 84.4% on time across 6,748 flights.

On time

78.8%

National average is 77.3%

Avg delay

73 min

Across delayed flights only

Cancelled

1.02%

National rate is 1.89%

Largest base

DEN

107,895 departures, 78.9% on time

These figures cover 831,000 flights between September 2025 and August 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. New Orleans (MSY) arrives on time 84.4% of the time; New York (LGA) manages 71.4%. Sample sizes sit next to every figure, because a two-point gap across 9,068 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	107,895	78.9%	65 min	0.41%	B+
ORD · Chicago	102,132	73.0%	73 min	1.30%	C
IAH · Houston	74,201	80.6%	63 min	0.55%	B+
EWR · Newark	68,308	76.3%	77 min	2.30%	B
SFO · San Francisco	62,048	79.8%	58 min	0.46%	B+
IAD · Washington	36,915	82.1%	73 min	0.85%	B+
LAX · Los Angeles	29,614	82.5%	62 min	0.50%	B+
LAS · Las Vegas	15,169	79.5%	71 min	0.63%	B+
MCO · Orlando	15,054	81.5%	83 min	1.11%	B
BOS · Boston	13,042	77.7%	78 min	1.92%	B
AUS · Austin	10,877	80.1%	75 min	1.12%	B
SAN · San Diego	10,655	79.7%	69 min	0.71%	B+
PHX · Phoenix	10,074	80.3%	77 min	0.78%	B+
DFW · Dallas-Fort Worth	10,062	76.6%	86 min	1.62%	B
LGA · New York	9,068	71.4%	88 min	3.11%	C−
FLL · Fort Lauderdale	9,046	82.6%	81 min	1.15%	B
CLE · Cleveland	8,949	84.2%	81 min	0.92%	B+
SEA · Seattle	8,683	79.9%	74 min	0.75%	B+
TPA · Tampa	8,554	82.2%	76 min	0.85%	B+
ATL · Atlanta	7,672	79.7%	84 min	1.51%	B
BNA · Nashville	7,009	76.2%	85 min	1.48%	B
DCA · Washington	6,887	77.6%	84 min	1.63%	B
MIA · Miami	6,757	78.7%	84 min	1.11%	B
MSY · New Orleans	6,748	84.4%	78 min	0.71%	B+
PDX · Portland	6,624	80.6%	65 min	0.59%	B+

New York (LGA) cancels 3.1% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Route by route

Busiest United Airlines routes

These are the 25 routes United Airlines flies most often, each against its network-wide 78.8%. 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	4,671	65.4%	90 min	4.24%	C−
ORD to LGA	4,671	66.1%	83 min	3.98%	C−
EWR to ORD	4,415	70.3%	80 min	2.83%	C
ORD to EWR	4,415	72.0%	89 min	2.85%	C
IAH to ORD	4,084	78.2%	69 min	0.59%	B+
ORD to IAH	4,080	80.0%	70 min	0.66%	B+
MCO to EWR	4,019	78.6%	95 min	2.36%	B
EWR to MCO	4,019	79.8%	77 min	2.21%	B
DEN to IAH	3,894	79.7%	63 min	0.26%	B+
IAH to DEN	3,894	83.6%	67 min	0.23%	B+
ORD to DEN	3,888	78.3%	76 min	0.87%	B+
DEN to ORD	3,885	71.9%	82 min	0.82%	C+
SFO to ORD	3,885	76.6%	70 min	0.67%	B+
ORD to SFO	3,883	69.1%	75 min	0.82%	C+
EWR to SFO	3,863	66.7%	90 min	2.43%	C
SFO to EWR	3,861	75.2%	79 min	2.07%	B
SFO to IAH	3,578	84.0%	50 min	0.25%	B+
IAH to SFO	3,578	78.2%	62 min	0.42%	B+
EWR to LAX	3,527	71.0%	84 min	1.93%	C
LAX to EWR	3,526	77.7%	77 min	1.76%	B
IAH to EWR	3,510	75.2%	72 min	1.57%	B
EWR to IAH	3,510	80.8%	77 min	1.60%	B
DEN to SFO	3,429	69.0%	63 min	0.23%	C+
SFO to DEN	3,427	82.1%	58 min	0.18%	B+
IAH to LAX	3,421	85.7%	57 min	0.20%	A+

Flight by flight

Busiest United Airlines flight numbers

United Airlines has 833 flight numbers that flew one route often enough to report a rate. These are the busiest; the full list is one click away.

All 833 United Airlines flight numbers

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 20 points, against 13 points between the best and worst airport.

5am–8am129,330 flights89.6%
8am–11am170,476 flights84.4%
11am–2pm149,877 flights80.5%
2pm–5pm144,848 flights73.2%
5pm–8pm147,944 flights69.2%
8pm–5am88,350 flights75.0%

Scale runs 60% to 95%.

Book the early departure. Flights leaving between 5am–8am arrive on time 89.6% of the time, against 69.2% for the evening window. That is 20 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 170,476 flights scheduled in it.

Across the year

United Airlines through the calendar

United's year swings by 12 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, August worst

August is the worst month at 71.9% on time, 12 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. July was the busiest month here, with 74,440 flights.

Across the week, Tuesday is the strongest day at 82.7% on time and Sunday the weakest at 75.4%, a spread of 7 points.

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 12.6 million reported delay minutes.

Late-arriving aircraft
36%
National Airspace System
35%
Carrier
25%
Extreme weather
4%
Security
0%

36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 12.6 million reported delay minutes here, that single category outweighs weather by 9 to one. The split is drawn from 12,618,531 reported delay minutes.

35% 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 4.38 million minutes out of 12.6 million, against a national NAS share of 21%.

Cancellations sit at 1.02% against a national 1.89%, which is ordinary. Diversions add another 0.33%.

7.8% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.

830,825 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 August 71.9%, a swing of 12 points. If the dates move at all, move them out of August before you think about anything else. 819,606 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 arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.2% of the 830,825 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.

Which airport does United Airlines run best from?

New Orleans (MSY) leads at 84.4% on time across 6,748 flights. New York (LGA) is at the other end on 71.4%, 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 69.2%, 20 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 August delays on United Airlines?

August is the weakest month at 71.9% on time, compared with 84.2% in February. Across the year that is 12 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, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures