Carrier route record
WNSAN→PHX
Southwest Airlines · San Diego to Phoenix
- Flights
- 3,184
- Period
- July 2025 to June 2026
- Share of route
- 54%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on SAN to PHX 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 77.6%. The late ones land about 50 minutes behind schedule. That rests on 3,184 flights. The strongest carrier on the route with a full sample, American Airlines, flew 1,669 at 81.3% on time.
American Airlines is the most reliable of the three carriers covered here at 81.3% on time across 1,669 flights.
Key figures
On time
74.4%
Arrivals under 15 minutes late, of 3,132 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
1.54%
National rate is 1.81%
Whole route
75.8%
Every carrier on SAN to PHX, 5,920 flights
These figures cover 3,184 flights between July 2025 and June 2026. The median arrival is 4 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
Southwest against every carrier on SAN to PHX
Southwest flew 3,184 of the 5,920 flights on SAN to PHX, most of the route. Its 74.4% on time is about level with the route as a whole at 75.8%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from American at 81.3% to SkyWest at 67.8%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. American Airlines arrives on time 81.3% of the time; SkyWest Airlines manages 67.8%. Sample sizes sit next to every figure, because a two-point gap across 445 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines | 1,669 | 81.3% | 118 min | 0.72% | B+ |
| Alaska Airlinesthin sample | 217 | 77.9% | 46 min | 1.84% | B |
| Southwest Airlines (this page) | 3,184 | 74.4% | 50 min | 1.54% | C |
| Frontier Airlines | 405 | 70.9% | 74 min | 1.23% | C |
| SkyWest Airlines | 445 | 67.8% | 54 min | 5.17% | C− |
SkyWest Airlines cancels 5.2% 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.
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 31 points, against 14 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am411 flights89.9%
- 8am–11am642 flights86.2%
- 11am–2pm462 flights76.9%
- 2pm–5pm660 flights67.9%
- 5pm–8pm569 flights59.0%
- 8pm–5am440 flights69.8%
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 59.0% on time, against 89.9% 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 2pm–5pm window is the busiest, with 660 flights scheduled in it.
Across the year
Southwest on SAN to PHX through the year
June is the worst month at 62.8% on time, 18 points below February, the best at 80.7%. 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. October was the busiest month here, with 290 flights.
Across the week, Saturday is the strongest day at 84.6% on time and Friday the weakest at 64.9%. 20 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 66% of the 40,000 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.
- 66%Late-arriving aircraft
- 21%Carrier
- 12%National Airspace System
- 0%Extreme weather
- 0%Security
66% 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 40,000 reported delay minutes here, that single category outweighs weather by 66 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 39,841 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 89.9% on time here.
Cancellations sit at 1.54% against a national 1.81%, which is ordinary. Diversions add another 0.09%.
Connections and stage length
What a delay here costs
6.5% 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 last about 50 minutes, which a normal layover absorbs.
At 304 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 runs 71.7% on time across 3,193 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 3,184 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 Southwest on SAN to PHX
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 80.7% on time and June 62.8%, a swing of 18 points. If the dates move at all, move them out of June before you think about anything else. 3,132 completed flights over 12 months sit behind that.
Related
Where to go next
- SAN to PHX, every carrier
- Southwest on PHX to SAN, the return leg
- American Airlines on SAN to PHX81.3%
- Alaska Airlines on SAN to PHX77.9%
- Frontier Airlines on SAN to PHX70.9%
- SkyWest Airlines on SAN to PHX67.8%
- Southwest Airlines network-wide record
- San Diego International (SAN) delay statistics
- Phoenix Sky Harbor International (PHX) delay statistics
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.