Carrier route record

WNSAT→PHX

Southwest Airlines · San Antonio to Phoenix

Flights: 1,390
Period: July 2025 to June 2026
Share of route: 55%
Carriers: 4

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.

Southwest on SAT to PHX lands a B+, 6 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That is a workable record, not a spotless one. That rests on 1,390 flights, with a median arrival 8 minutes early.

Set against the rest of the country, Southwest's SAT to PHX record is 6 points better than the US average of 77.6%. That gap is worth roughly 57 fewer late arrivals for every thousand flights.

On time

83.3%

Arrivals under 15 minutes late, of 1,386 completed flights

Avg delay

51 min

Across delayed arrivals only, not all flights

Cancelled

0.22%

National rate is 1.81%

Whole route

81.9%

Every carrier on SAT to PHX, 2,512 flights

These figures cover 1,390 flights between July 2025 and June 2026. The median arrival is 8 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 SAT to PHX

Southwest flew 1,390 of the 2,512 flights on SAT to PHX, most of the route. Its 83.3% on time is about level with the route as a whole at 81.9%. Ranked by on-time rate it is first of four carriers on the route, where the range runs from Southwest at 83.3% to Envoy at 64.1%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on SAT to PHX
Airline	Flights	On time	Avg delay	Cancelled	Grade
Southwest Airlines (this page)	1,390	83.3%	51 min	0.22%	B+
Frontier Airlinesthin sample	65	83.1%	57 min	0.00%	B+
American Airlines	1,018	80.6%	115 min	0.98%	B+
Envoy Airthin sample	39	64.1%	37 min	0.00%	D+

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 27 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am335 flights97.3%
8am–11am64 flights90.6%
11am–2pm363 flights89.2%
2pm–5pm190 flights72.0%
5pm–8pm251 flights72.5%
8pm–5am187 flights70.4%

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 97.3% of the time, against 70.4% for the overnight window. That is 27 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 363 flights scheduled in it.

Across the year

Southwest on SAT to PHX through the year

Darker means more delays. Figures are on-time percentages.March best, June worst

June is the worst month at 61.3% on time, 30 points below March, the best at 91.1%. 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. May was the busiest month here, with 139 flights.

Across the week, Tuesday is the strongest day at 91.0% on time and Sunday the weakest at 77.7%. 13 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 58% of the 12,000 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
58%
Carrier
24%
National Airspace System
14%
Extreme weather
3%
Security
0%

58% 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 12,000 reported delay minutes here, that single category outweighs weather by 18 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 11,690 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 97.3% on time here.

Cancellations are rare at 0.22%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 4.2% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The 843 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg is a different operation and performs like one: it runs 74.6% on time across 1,388 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 1,390 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 SAT to PHX

Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 91.1% on time and June 61.3%, a swing of 30 points. If the dates move at all, move them out of June before you think about anything else. 1,386 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures