Route reliability record

SAN→LAS

San Diego to Las Vegas

Flights: 5,868
Period: July 2025 to June 2026
Distance: 258 mi
Carriers: 4

This route sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 5,868 flights, of which SkyWest Airlines flew 1,491 at 78.9% on time.

SkyWest Airlines is the most reliable of the three carriers covered here at 78.9% on time across 1,491 flights.

On time

75.6%

Arrivals under 15 minutes late, of 5,785 completed flights

Avg delay

61 min

Across delayed arrivals only, not all flights

Cancelled

1.33%

National rate is 1.81%

Best carrier

SkyWest

78.9% on time across 1,491 flights

These figures cover 5,868 flights between July 2025 and June 2026. The median arrival is 5 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 airline is most reliable on SAN to LAS

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 78.9% of the time; Frontier Airlines manages 66.6%. Sample sizes sit next to every figure, because a two-point gap across 389 flights means less than a ten-point one.

On-time performance by carrier on SAN to LAS
Airline	Flights	On time	Avg delay	Cancelled	Grade
Spirit Airlinesthin sample	258	84.2%	65 min	1.94%	B
SkyWest Airlines	1,491	78.9%	70 min	1.34%	B
Southwest Airlines	3,730	74.7%	53 min	1.21%	C
Frontier Airlines	389	66.6%	95 min	2.06%	C

The spread between SkyWest and Frontier 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 29 points, against 12 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am645 flights95.5%
8am–11am1,223 flights86.3%
11am–2pm1,019 flights72.1%
2pm–5pm1,112 flights67.5%
5pm–8pm1,160 flights69.4%
8pm–5am709 flights66.6%

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 95.5% of the time, against 66.6% for the overnight window. That is 29 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 1,223 flights scheduled in it.

Across the year

When delays peak on this route

This route'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.January best, June worst

June is the worst month at 67.6% on time, 15 points below January, the best at 83.0%. 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 84.8% on time and Friday the weakest at 65.2%. 20 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 51% of the 86,000 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
51%
Carrier
23%
National Airspace System
22%
Extreme weather
4%
Security
0%

51% 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 86,000 reported delay minutes here, that single category outweighs weather by 13 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 85,528 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 95.5% on time here.

Cancellations sit at 1.33% against a national 1.81%, which is ordinary. Diversions add another 0.09%.

Connections and stage length

What a delay here actually costs

7.8% 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.

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 66.7% on time across 5,877 flights, 9 points below 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 5,868 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. January runs 83.0% on time and June 67.6%, a swing of 15 points. If the dates move at all, move them out of June before you think about anything else. 5,785 completed flights over 12 months sit behind that.

Common questions

SAN to LAS questions

How often is SAN to LAS delayed?

About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 24.4% of the 5,868 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on SAN to LAS?

SkyWest Airlines leads at 78.9% on time across 1,491 flights. Frontier Airlines is at the other end on 66.6%, 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 SAN to LAS?

The 5am–8am departure window is the strongest at 95.5% on time. The 8pm–5am window is the weakest at 66.6%, 29 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 SAN to LAS?

June is the weakest month at 67.6% on time, compared with 83.0% in January. 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

Direction matters. SAN to LAS and LAS to SAN 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