Las Vegas, NV · departure reliability

LAS

Harry Reid International

Departures: 174,350
Period: July 2025 to June 2026
Carriers: 11
US rank: #8 by volume

Terminal building and aircraft stands at a US airport

Las Vegas

Harry Reid International lands a B+, level with the national rate of 77.6%. Roughly one flight in five arrive 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 174,350 flights, of which Delta Air Lines flew 15,755 at 85.6% on time.

Delta Air Lines is the most reliable of the eleven carriers covered here at 85.6% on time across 15,755 flights.

On time

77.9%

Departures arriving under 15 minutes late at their destination

Avg delay

61 min

Across delayed flights only

Cancelled

0.87%

National rate is 1.81%

Best carrier

Delta

85.6% on time here

These figures cover 174,000 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.

Carrier by carrier

Which airlines run best out of LAS

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 85.6% of the time; Hawaiian Airlines manages 69.4%. Sample sizes sit next to every figure, because a two-point gap across 855 flights means less than a ten-point one.

On-time performance by carrier departing LAS
Airline	Flights	On time	Avg delay	Cancelled	Grade
Southwest Airlines	86,261	74.3%	50 min	0.58%	C+
Delta Air Lines	15,755	85.6%	77 min	1.00%	A
United Airlines	15,170	80.7%	67 min	0.66%	B+
American Airlines	14,073	81.5%	95 min	1.86%	B
Frontier Airlines	12,272	77.7%	76 min	1.25%	B
Spirit Airlines	8,396	82.8%	77 min	1.49%	B
Allegiant Air	7,115	83.8%	74 min	0.45%	B+
Alaska Airlines	6,759	79.4%	60 min	1.02%	B
JetBlue Airways	3,919	78.6%	78 min	1.91%	B
SkyWest Airlines	3,769	80.6%	71 min	1.01%	B
Hawaiian Airlines	855	69.4%	86 min	0.47%	C+

The spread between Delta and Hawaiian is 16 points, wide enough that it should decide the booking. On a hundred trips that is 16 more arrivals inside the on-time window.

Route by route

Busiest routes out of LAS

Route-level records vary far more than the airport average. These are the 25 busiest departures from LAS, each with its own on-time rate against the airport-wide 77.9%.

Busiest routes from LAS by flight volume
Route	Flights	On time	Avg delay	Cancelled	Grade
LAS to LAX · Los Angeles	8,325	78.8%	60 min	0.70%	B+
LAS to DEN · Denver	7,088	77.0%	66 min	0.87%	B+
LAS to SFO · San Francisco	6,060	62.8%	59 min	0.68%	D+
LAS to PHX · Phoenix	6,025	78.2%	65 min	1.00%	B
LAS to SAN · San Diego	5,877	66.7%	55 min	1.11%	C
LAS to SEA · Seattle	5,649	82.3%	63 min	0.94%	B+
LAS to ORD · Chicago	5,297	76.5%	79 min	1.25%	B
LAS to DFW · Dallas-Fort Worth	5,173	80.2%	99 min	2.84%	B
LAS to ATL · Atlanta	4,791	85.2%	72 min	0.88%	A+
LAS to SNA · Santa Ana	4,252	81.9%	56 min	0.73%	B+
LAS to SMF · Sacramento	4,239	78.2%	58 min	0.57%	B+
LAS to BUR · Burbank	4,185	79.8%	58 min	1.34%	B
LAS to RNO · Reno	4,020	79.7%	57 min	0.80%	B+
LAS to SJC · San Jose	3,844	78.3%	54 min	0.39%	B+
LAS to SLC · Salt Lake City	3,741	82.8%	61 min	0.70%	B+
LAS to JFK · New York	3,710	81.3%	87 min	2.40%	B
LAS to IAH · Houston	3,455	83.9%	75 min	0.93%	B+
LAS to OAK · Oakland	3,319	71.6%	52 min	0.42%	C+
LAS to EWR · Newark	2,990	81.4%	81 min	1.61%	B
LAS to PDX · Portland	2,984	78.8%	56 min	0.60%	B+
LAS to AUS · Austin	2,865	73.5%	55 min	0.42%	C+
LAS to DAL · Dallas	2,860	71.5%	50 min	1.71%	C
LAS to DTW · Detroit	2,838	81.7%	71 min	0.60%	B+
LAS to ONT · Ontario	2,479	75.8%	55 min	0.77%	B+
LAS to MDW · Chicago	2,346	76.3%	49 min	0.85%	B+

Departure window

The best time of day to leave LAS

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against 16 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am26,804 flights91.6%
8am–11am36,283 flights84.2%
11am–2pm30,418 flights77.1%
2pm–5pm28,639 flights70.4%
5pm–8pm24,514 flights68.6%
8pm–5am27,692 flights73.3%

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 91.6% of the time, against 68.6% for the evening window. That is 23 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 36,283 flights scheduled in it.

Across the year

When LAS runs late

LAS'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.January best, June worst

June is the worst month at 70.7% on time, 12 points below January, the best at 83.1%. 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 15,733 flights.

Across the week, Saturday is the strongest day at 83.7% on time and Friday the weakest at 74.1%. 10 points is a smaller lever than departure hour, but it is free.

Delay causes

Why LAS gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 2.32 million 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.

Late-arriving aircraft
44%
Carrier
35%
National Airspace System
19%
Extreme weather
2%
Security
0%

44% 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 2.32 million reported delay minutes here, that single category outweighs weather by 19 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 2,319,618 reported delay minutes.

The largest share of delay minutes, 35%, 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 804,000 of the 2.32 million delay minutes reported here.

Cancellations are rare at 0.87%, 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.

6.6% 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 about an hour kind, which a normal layover absorbs.

174,350 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

Flying out of LAS

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 83.1% on time and June 70.7%, a swing of 12 points. If the dates move at all, move them out of June before you think about anything else. 172,368 completed flights over 12 months sit behind that.

Common questions

LAS delay questions

How often is Las Vegas (LAS) delayed?

Roughly 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 22.1% of the 174,350 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on Las Vegas (LAS)?

Delta Air Lines leads at 85.6% on time across 15,755 flights. Hawaiian Airlines is at the other end on 69.4%, a gap of 16 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 Las Vegas (LAS)?

The 5am–8am departure window is the strongest at 91.6% on time. The 5pm–8pm window is the weakest at 68.6%, 23 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 June delays on Las Vegas (LAS)?

June is the weakest month at 70.7% on time, compared with 83.1% in January. 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, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures