Route reliability record

LAS→SAN

Las Vegas to San Diego

Flights: 5,877
Period: July 2025 to June 2026
Distance: 258 mi
Carriers: 5

This route draws a C. About one flight in three arrive at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 5,877 flights, of which SkyWest Airlines flew 1,492 at 74.6% on time.

SkyWest Airlines is the most reliable of the three carriers covered here at 74.6% on time across 1,492 flights.

On time

66.7%

Arrivals under 15 minutes late, of 5,804 completed flights

Avg delay

55 min

Across delayed arrivals only, not all flights

Cancelled

1.11%

National rate is 1.81%

Best carrier

SkyWest

74.6% on time across 1,492 flights

These figures cover 5,877 flights between July 2025 and June 2026. Beyond the headline rate, 9.0% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Which airline is most reliable on LAS to SAN

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 74.6% of the time; Southwest Airlines manages 62.5%. Sample sizes sit next to every figure, because a two-point gap across 3,738 flights means less than a ten-point one.

On-time performance by carrier on LAS to SAN
Airline	Flights	On time	Avg delay	Cancelled	Grade
Alaska Airlinesthin sample	1	100.0%	—	0.00%	A+
Spirit Airlinesthin sample	257	78.7%	72 min	1.17%	B
SkyWest Airlines	1,492	74.6%	63 min	1.34%	C
Frontier Airlines	389	68.2%	91 min	1.29%	C
Southwest Airlines	3,738	62.5%	50 min	0.99%	D+

The spread between SkyWest and Southwest is 12 points, wide enough that it should decide the booking. On a hundred trips that is 12 more arrivals inside the on-time window.

Departure window

The best time of day to leave

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 31 points, against 12 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am861 flights87.7%
8am–11am1,209 flights71.6%
11am–2pm922 flights62.3%
2pm–5pm1,134 flights64.4%
5pm–8pm989 flights56.4%
8pm–5am762 flights56.7%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 56.4% on time, against 87.7% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 1,209 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 19 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.August best, June worst

June is the worst month at 53.9% on time, 19 points below August, the best at 72.7%. 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. August was the busiest month here, with 656 flights.

Across the week, Wednesday is the strongest day at 77.8% on time and Friday the weakest at 57.5%. 20 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

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 107,000 reported delay minutes.

Late-arriving aircraft
35%
Carrier
32%
National Airspace System
30%
Extreme weather
2%
Security
0%

35% 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 107,000 reported delay minutes here, that single category outweighs weather by 15 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 106,969 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.7% on time here.

Cancellations sit at 1.11% against a national 1.81%, which is ordinary. Diversions add another 0.14%.

Connections and stage length

What a delay here actually costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.0% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

At 258 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 75.6% on time across 5,868 flights, 9 points above 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 9 points of difference.

The sample behind these figures is 5,877 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. August runs 72.7% on time and June 53.9%, a swing of 19 points. If the dates move at all, move them out of June before you think about anything else. 5,804 completed flights over 12 months sit behind that.

Common questions

LAS to SAN questions

How often is LAS to SAN delayed?

About one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 33.3% of the 5,877 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 to SAN?

SkyWest Airlines leads at 74.6% on time across 1,492 flights. Southwest Airlines is at the other end on 62.5%, a gap of 12 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 to SAN?

The 5am–8am departure window is the strongest at 87.7% on time. The 5pm–8pm window is the weakest at 56.4%, 31 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 to SAN?

June is the weakest month at 53.9% on time, compared with 72.7% in August. Across the year that is 19 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

Direction matters. LAS to SAN and SAN to LAS are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

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