Airport month record
SATSEP
San Antonio International in September 2025
- Departures
- 3,334
- Month
- September 2025
- National, same month
- 83.4%
- Carriers
- 9
Historical statistics for September 2025, not live status or a forecast for this year’s September. For today’s conditions at SAT, see live FAA status.
SAT in September earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 2 points better than the national rate of 83.4%. When something does go wrong the average delay runs a little over an hour. That rests on 3,334 flights, of which Southwest Airlines flew 1,257 at 86.3% on time.
Southwest Airlines is the most reliable of the four carriers covered here at 86.3% on time across 1,257 flights.
Key figures
On time
85.6%
Arrivals under 15 minutes late, of 3,304 completed departures
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
0.63%
Nationally in September: 0.51%
Whole year
81.8%
SAT across all twelve months
These figures cover 3,334 departures from San Antonio International in September 2025. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.
Against the year
September next to SAT's other months
Against SAT's own year, September ran 4 points better than the twelve-month rate of 81.8%, which makes it number two of twelve months, best first. Cancellations were unusually low for SAT in September, at 0.63% against 1.28% across the year. Either side of it, August ran 81.5% on time and October 83.7%, so a trip moved by a few weeks would have landed in a worse stretch.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| July 2025 | 3,699 | 76.4% | 77 min | 1.49% | B |
| August 2025 | 3,444 | 81.5% | 79 min | 1.19% | B |
| September 2025 (this page) | 3,334 | 85.6% | 71 min | 0.63% | A+ |
| October 2025 | 3,656 | 83.7% | 68 min | 0.38% | B+ |
| November 2025 | 3,440 | 84.1% | 67 min | 1.19% | B |
| December 2025 | 3,588 | 83.7% | 66 min | 0.72% | B+ |
| January 2026 | 2,921 | 84.8% | 96 min | 3.70% | B− |
| February 2026 | 2,671 | 86.3% | 67 min | 1.27% | A |
| March 2026 | 3,439 | 79.9% | 74 min | 1.37% | B |
| April 2026 | 3,384 | 82.6% | 66 min | 0.74% | B+ |
| May 2026 | 3,485 | 80.7% | 79 min | 1.38% | B |
| June 2026 | 3,393 | 73.5% | 81 min | 1.65% | C |
Departure window
The best time of day to leave SAT in September
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 17 points, against about a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am921 flights92.0%
- 8am–11am468 flights92.6%
- 11am–2pm708 flights86.7%
- 2pm–5pm598 flights80.0%
- 5pm–8pm497 flights75.2%
- 8pm–5am142 flights75.9%
Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 92.6% of the time, against 75.2% for the evening window. That is 17 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 921 flights scheduled in it.
Across the week, Tuesday is the strongest day at 90.3% on time and Thursday the weakest at 81.1%. 9 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at SAT in September
The four carriers here are closely matched: about a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 1,257 | 86.3% | 47 min | 0.24% | A+ |
| American Airlines | 602 | 85.2% | 114 min | 1.83% | A |
| Delta Air Lines | 568 | 86.2% | 71 min | 0.18% | A+ |
| United Airlines | 504 | 85.4% | 51 min | 0.20% | A+ |
| Spirit Airlinesthin sample | 108 | 76.4% | 113 min | 1.85% | B |
| SkyWest Airlinesthin sample | 92 | 88.0% | 81 min | 0.00% | A+ |
| Frontier Airlinesthin sample | 68 | 85.3% | 98 min | 0.00% | A+ |
| Envoy Airthin sample | 60 | 79.3% | 83 min | 3.33% | B− |
| Alaska Airlinesthin sample | 47 | 93.6% | 95 min | 0.00% | A+ |
No carrier stands out. Southwest tops the table at 86.3%, about a point clear of the bottom, which is inside the range this kind of sample moves year to year.
Route by route
Busiest routes out of SAT in September
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SAT to DFW · Dallas-Fort Worth | 367 | 83.1% | 115 min | 3.27% | B− |
| SAT to ATL · Atlantathin sample | 260 | 94.6% | 61 min | 0.00% | A+ |
| SAT to IAH · Houstonthin sample | 229 | 83.0% | 37 min | 0.00% | B+ |
| SAT to DAL · Dallasthin sample | 219 | 88.0% | 46 min | 0.91% | A+ |
| SAT to DEN · Denverthin sample | 219 | 82.9% | 55 min | 0.46% | B+ |
| SAT to LAS · Las Vegasthin sample | 189 | 78.7% | 74 min | 0.53% | B+ |
| SAT to PHX · Phoenixthin sample | 171 | 84.5% | 107 min | 1.17% | B |
| SAT to LAX · Los Angelesthin sample | 155 | 89.0% | 61 min | 0.00% | A+ |
| SAT to ORD · Chicagothin sample | 151 | 81.3% | 63 min | 0.66% | B+ |
| SAT to HOU · Houstonthin sample | 141 | 83.0% | 47 min | 0.00% | B+ |
| SAT to CLT · Charlottethin sample | 120 | 90.0% | 67 min | 0.00% | A+ |
| SAT to DTW · Detroitthin sample | 82 | 92.7% | 40 min | 0.00% | A+ |
| SAT to SLC · Salt Lake Citythin sample | 77 | 76.3% | 54 min | 1.30% | B |
| SAT to MSP · Minneapolisthin sample | 77 | 81.6% | 105 min | 0.00% | B+ |
| SAT to BNA · Nashvillethin sample | 73 | 91.8% | 32 min | 0.00% | A+ |
| SAT to ELP · El Pasothin sample | 73 | 80.8% | 46 min | 0.00% | B+ |
| SAT to BWI · Baltimorethin sample | 69 | 89.9% | 34 min | 0.00% | A+ |
| SAT to MCO · Orlandothin sample | 67 | 88.1% | 123 min | 0.00% | A+ |
| SAT to SAN · San Diegothin sample | 56 | 81.8% | 68 min | 0.00% | B+ |
| SAT to MDW · Chicagothin sample | 56 | 85.7% | 43 min | 0.00% | A+ |
| SAT to IAD · Washingtonthin sample | 51 | 94.1% | 164 min | 0.00% | A+ |
| SAT to SEA · Seattlethin sample | 47 | 93.6% | 95 min | 0.00% | A+ |
| SAT to STL · St. Louisthin sample | 47 | 93.6% | 27 min | 0.00% | A+ |
| SAT to SFO · San Franciscothin sample | 35 | 94.3% | 38 min | 0.00% | A+ |
| SAT to EWR · Newarkthin sample | 34 | 84.4% | 132 min | 0.00% | B+ |
Delay causes
What held SAT up in September
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 34,000 reported delay minutes.
- 38%Late-arriving aircraft
- 30%Carrier
- 25%National Airspace System
- 7%Extreme weather
- 0%Security
38% 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 34,000 reported delay minutes here, that single category outweighs weather by 5 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 33,510 reported delay minutes.
Cancellations are rare at 0.63%, below the national 0.51% 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.
Badly late arrivals are rare here: only 4.6% land an hour or more behind schedule, against 5.4% 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.
What to do with this
Flying from SAT in September
For a September trip through SAT: this is one of the better months to be flying from here, 85.6% on time with 0.63% cancelled. That is a base rate for the month as a whole; a single storm can still spoil a particular day.
Related
Where to go next
- San Antonio International (SAT), the whole year
- SAT in July76.4%
- SAT in August81.5%
- SAT in October83.7%
- SAT in November84.1%
- SAT in December83.7%
- SAT in January84.8%
- SAT in February86.3%
- SAT in March79.9%
- SAT in April82.6%
- SAT in May80.7%
- SAT in June73.5%
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.