Carrier performance at one airport
WN→SAN
Southwest Airlines at San Diego International
- Departures
- 39,067
- Period
- September 2025 to August 2026
- Routes
- 25
- Rank here
- #8 of 8
Southwest Airlines at San Diego sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land about 50 minutes behind schedule. That rests on 39,067 flights, of which Delta Air Lines flew 9,581 at 86.3% on time.
Measured against the airport rather than the country, Southwest Airlines runs 6 points behind the 76.3% 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.
Key figures
On time
70.6%
38,613 completed departures
Avg delay
51 min
Across delayed flights only
Cancelled
0.92%
At SAN, this carrier only
Rank here
#8
Of 8 carriers clearing the floor at SAN
These figures cover 39,000 flights between September 2025 and August 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
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; Southwest Airlines manages 70.6%. Sample sizes sit next to every figure, because a two-point gap across 39,067 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 9,581 | 86.3% | 79 min | 1.17% | A |
| American Airlines | 9,387 | 80.6% | 103 min | 1.64% | B |
| United Airlines | 10,655 | 79.7% | 69 min | 0.71% | B+ |
| Alaska Airlines | 13,373 | 79.0% | 57 min | 1.35% | B |
| JetBlue Airways | 1,643 | 78.8% | 97 min | 3.16% | B− |
| SkyWest Airlines | 14,921 | 77.8% | 58 min | 2.01% | B |
| Frontier Airlines | 2,105 | 71.5% | 81 min | 1.95% | C |
| Southwest Airlines (this page) | 39,067 | 70.6% | 51 min | 0.92% | C+ |
JetBlue Airways cancels 3.2% 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
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.
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SAN to SMF · Sacramento | 3,798 | 73.0% | 47 min | 0.61% | C+ |
| SAN to SJC · San Jose | 3,752 | 72.6% | 49 min | 0.77% | C+ |
| SAN to LAS · Las Vegas | 3,727 | 72.6% | 53 min | 1.53% | C |
| SAN to PHX · Phoenix | 3,210 | 71.6% | 50 min | 1.43% | C |
| SAN to OAK · Oakland | 2,933 | 72.4% | 50 min | 0.95% | C+ |
| SAN to DEN · Denver | 2,404 | 71.0% | 58 min | 0.71% | C+ |
| SAN to SFO · San Francisco | 2,070 | 52.4% | 61 min | 1.30% | F |
| SAN to DAL · Dallas | 1,592 | 66.8% | 46 min | 1.63% | C |
| SAN to AUS · Austin | 1,457 | 64.6% | 51 min | 0.55% | D+ |
| SAN to BWI · Baltimore | 1,182 | 76.6% | 45 min | 1.69% | B |
| SAN to MDW · Chicago | 1,110 | 76.7% | 48 min | 1.08% | B |
| SAN to BNA · Nashville | 1,107 | 72.6% | 45 min | 1.08% | C |
| SAN to HOU · Houston | 985 | 69.6% | 45 min | 0.41% | C+ |
| SAN to RNO · Reno | 969 | 70.5% | 50 min | 0.83% | C+ |
| SAN to HNL · Honolulu | 729 | 78.9% | 46 min | 0.82% | B+ |
| SAN to ABQ · Albuquerque | 683 | 75.2% | 56 min | 0.73% | B+ |
| SAN to TUS · Tucson | 663 | 75.6% | 66 min | 0.30% | B+ |
| SAN to FAT · Fresno | 627 | 79.2% | 45 min | 1.12% | B |
| SAN to SAT · San Antonio | 611 | 68.0% | 53 min | 0.65% | C+ |
| SAN to STL · St. Louis | 470 | 71.7% | 50 min | 0.21% | C+ |
| SAN to MCO · Orlando | 459 | 78.3% | 43 min | 0.65% | B+ |
| SAN to SLC · Salt Lake City | 436 | 72.8% | 45 min | 0.23% | C+ |
| SAN to BOI · Boise | 426 | 73.0% | 55 min | 0.00% | C+ |
| SAN to MCI · Kansas City | 384 | 68.1% | 51 min | 0.78% | C+ |
| SAN to ELP · El Pasothin sample | 357 | 67.2% | 53 min | 0.56% | 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 33 points, against 16 points between the best and worst carrier.
- 5am–8am5,260 flights91.4%
- 8am–11am8,844 flights83.5%
- 11am–2pm6,582 flights66.1%
- 2pm–5pm6,913 flights58.3%
- 5pm–8pm6,980 flights60.2%
- 8pm–5am4,488 flights62.5%
Scale runs 50% to 95%.
Book the early departure. Flights leaving between 5am–8am arrive on time 91.4% of the time, against 58.3% for the afternoon window. That is 33 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 8,844 flights scheduled in it.
Across the year
Seasonal pattern
August is the worst month at 55.4% on time, 27 points below January, the best at 82.5%. 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 3,741 flights.
Delay causes
What holds this operation up
- 63%Late-arriving aircraft
- 22%Carrier
- 14%National Airspace System
- 1%Extreme weather
- 0%Security
63% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 576,000 reported delay minutes here, that single category outweighs weather by 63 to one. The split is drawn from 575,879 reported delay minutes.
Cancellations sit at 0.92% against a national 1.89%, which is ordinary. Diversions add another 0.24%.
7.9% 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 about 50 minutes, which a normal layover absorbs.
39,067 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 August 55.4%, a swing of 27 points. If the dates move at all, move them out of August before you think about anything else. 38,613 completed flights over 12 months sit behind that.
Common questions
Southwest Airlines at SAN
How often is Southwest Airlines at SAN delayed?
Roughly one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 29.4% of the 39,067 flights in this analysis, against 22.7% 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 9,581 flights. Southwest Airlines is at the other end on 70.6%, 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 Southwest Airlines at SAN?
The 5am–8am departure window is the strongest at 91.4% on time. The 2pm–5pm window is the weakest at 58.3%, 33 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 Southwest Airlines at SAN?
August is the weakest month at 55.4% on time, compared with 82.5% in January. Across the year that is 27 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.