Carrier performance at one airport

WN→SAN

Southwest Airlines at San Diego International

Departures: 37,160
Period: June 2025 to May 2026
Routes: 25
Rank here: #8 of 10

Southwest Airlines at San Diego sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.4%. The late ones land about 50 minutes behind schedule. That rests on 37,160 flights, of which Delta Air Lines flew 9,609 at 86.3% on time.

Measured against the airport rather than the country, Southwest Airlines runs 4 points behind the 78.2% weighted average across all carriers at SAN. That is the comparison worth making: every operator here works the same runways, the same airspace and the same weather.

On time

74.7%

36,742 completed departures

Avg delay

51 min

Across delayed flights only

Cancelled

0.90%

At SAN, this carrier only

Rank here

Of 10 carriers clearing the floor at SAN

These figures cover 37,000 flights between June 2025 and May 2026. The median arrival is 3 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.

Against the competition

Every carrier at SAN, ranked

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 86.3% of the time; Hawaiian Airlines manages 58.5%. Sample sizes sit next to every figure, because a two-point gap across 562 flights means less than a ten-point one.

On-time performance of all carriers departing SAN
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	9,609	86.3%	74 min	1.09%	A
United Airlines	10,464	81.4%	69 min	0.75%	B+
JetBlue Airways	1,642	81.1%	105 min	2.13%	B
Spirit Airlines	539	81.0%	68 min	1.30%	B
American Airlines	9,361	80.5%	103 min	1.83%	B
SkyWest Airlines	14,980	79.4%	58 min	1.73%	B
Alaska Airlines	12,447	78.4%	58 min	1.46%	B
Southwest Airlines (this page)	37,160	74.7%	51 min	0.90%	C+
Frontier Airlines	2,332	70.3%	91 min	2.14%	C
Hawaiian Airlines	562	58.5%	72 min	1.42%	D

The spread between Delta and Hawaiian is 28 points, wide enough that it should decide the booking. On a hundred trips that is 28 more arrivals inside the on-time window.

Route by route

Where Southwest Airlines flies from SAN

Southwest Airlines operates 25 routes out of SAN with enough volume to report. Route records inside one carrier at one airport still spread widely, because a short shuttle and a transcontinental have very different exposure to a late inbound.

Southwest Airlines routes from SAN
Route	Flights	On time	Avg delay	Cancelled	Grade
SAN to SMF · Sacramento	3,818	76.4%	49 min	0.60%	B+
SAN to SJC · San Jose	3,748	77.2%	50 min	0.83%	B+
SAN to LAS · Las Vegas	3,725	75.4%	53 min	1.05%	B
SAN to PHX · Phoenix	3,193	75.6%	50 min	1.63%	B
SAN to OAK · Oakland	2,985	75.0%	49 min	1.24%	B
SAN to DEN · Denver	2,387	73.0%	59 min	0.84%	C+
SAN to SFO · San Francisco	1,886	61.5%	60 min	0.95%	D+
SAN to DAL · Dallas	1,570	71.1%	49 min	1.72%	C
SAN to AUS · Austin	1,428	71.5%	47 min	0.49%	C+
SAN to BWI · Baltimore	1,124	80.8%	47 min	1.33%	B
SAN to MDW · Chicago	1,067	77.0%	52 min	0.94%	B+
SAN to BNA · Nashville	1,037	75.8%	45 min	0.77%	B+
SAN to HOU · Houston	957	71.8%	43 min	0.42%	C+
SAN to RNO · Reno	912	76.4%	49 min	0.55%	B+
SAN to HNL · Honolulu	728	82.3%	46 min	0.82%	B+
SAN to ABQ · Albuquerque	687	78.4%	57 min	0.87%	B+
SAN to TUS · Tucson	653	75.8%	60 min	0.46%	B+
SAN to SAT · San Antonio	610	72.4%	49 min	0.33%	C+
SAN to STL · St. Louis	475	78.4%	50 min	0.21%	B+
SAN to FAT · Fresno	456	81.1%	45 min	1.32%	B
SAN to MCO · Orlando	408	77.4%	49 min	0.49%	B+
SAN to SLC · Salt Lake City	408	76.4%	44 min	0.25%	B+
SAN to MCI · Kansas City	395	75.6%	55 min	0.76%	B+
SAN to ELP · El Pasothin sample	357	80.6%	50 min	0.56%	B+
SAN to BOI · Boisethin sample	355	69.0%	53 min	0.00%	C+

Departure window

Best time of day for this operation

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 28 points, against 28 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am5,147 flights92.4%
8am–11am8,394 flights85.3%
11am–2pm6,454 flights71.6%
2pm–5pm6,511 flights64.9%
5pm–8pm6,751 flights65.5%
8pm–5am3,903 flights66.2%

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 92.4% of the time, against 64.9% for the afternoon window. That is 28 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on.

Across the year

Seasonal pattern

Darker means more delays. Figures are on-time percentages.January best, May worst

Delays peak in May, when the on-time rate falls to 68.5%. January is the strongest month at 82.5%. Moving a flexible trip across that boundary buys 14 points.

Delay causes

What holds this operation up

Late-arriving aircraft
61%
Carrier
22%
National Airspace System
15%
Extreme weather
1%
Security
0%

61% 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 473,000 reported delay minutes here, that single category outweighs weather by 61 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.

Cancellations sit at 0.90% against a national 1.80%, which is ordinary. Diversions add another 0.23%.

6.6% of arrivals land an hour or more late, close to the national 8.2%. 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 50 minutes kind, which a normal layover absorbs.

37,160 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.

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 82.5% on time and May 68.5%, a swing of 14 points. If the dates move at all, move them out of May before you think about anything else.

Common questions

Southwest Airlines at SAN

How often is Southwest Airlines at SAN 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 25.3% of the 37,160 flights in this analysis, against 22.6% nationally. Delayed flights are late by about 50 minutes on average.

Which airline is most reliable on Southwest Airlines at SAN?

Delta Air Lines leads at 86.3% on time across 9,609 flights. Hawaiian Airlines is at the other end on 58.5%, a gap of 28 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 Southwest Airlines at SAN?

The 5am–8am departure window is the strongest at 92.4% on time. The 2pm–5pm window is the weakest at 64.9%, 28 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 May delays on Southwest Airlines at SAN?

May is the weakest month at 68.5% on time, compared with 82.5% in January. Across the year that is 14 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, June 2025 to May 2026. Updated monthly. How this data is collected.

Key figures