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DelayAtlas

Airport month record

SATAUG

San Antonio International in August 2025

Departures
3,444
Month
August 2025
National, same month
77.4%
Carriers
9
BGRADE

Historical statistics for August 2025, not live status or a forecast for this year’s August. For today’s conditions at SAT, see live FAA status.

SAT in August lands a B, 4 points better than the national rate of 77.4%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 3,444 flights, of which Delta Air Lines flew 603 at 87.6% on time.

Delta Air Lines is the most reliable of the four carriers covered here at 87.6% on time across 603 flights.

Key figures

On time

81.5%

Arrivals under 15 minutes late, of 3,386 completed departures

Avg delay

79 min

Across delayed arrivals only, not all flights

Cancelled

1.19%

Nationally in August: 1.08%

Whole year

81.8%

SAT across all twelve months

These figures cover 3,444 departures from San Antonio International in August 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

August next to SAT's other months

Against SAT's own year, August ran level with the twelve-month rate of 81.8%, which makes it number eight of twelve months, best first. Either side of it, July ran 76.4% on time and September 85.6%, so this month sits in line with its neighbours.

SAT month by month
MonthFlightsOn timeAvg delayCancelledGrade
July 20253,69976.4%77 min1.49%B
August 2025 (this page)3,44481.5%79 min1.19%B
September 20253,33485.6%71 min0.63%A+
October 20253,65683.7%68 min0.38%B+
November 20253,44084.1%67 min1.19%B
December 20253,58883.7%66 min0.72%B+
January 20262,92184.8%96 min3.70%B−
February 20262,67186.3%67 min1.27%A
March 20263,43979.9%74 min1.37%B
April 20263,38482.6%66 min0.74%B+
May 20263,48580.7%79 min1.38%B
June 20263,39373.5%81 min1.65%C

Departure window

The best time of day to leave SAT in August

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 28 points, against 14 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am989 flights92.6%
  • 8am–11am498 flights87.9%
  • 11am–2pm639 flights83.1%
  • 2pm–5pm686 flights74.4%
  • 5pm–8pm515 flights64.9%
  • 8pm–5am117 flights67.5%

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

The 5pm–8pm window is where this operation falls apart: 64.9% on time, against 92.6% 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 5am–8am window is the busiest, with 989 flights scheduled in it.

Across the week, Tuesday is the strongest day at 88.8% on time and Thursday the weakest at 77.9%. 11 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week84.0Mon88.8Tue83.7Wed77.9Thu78.7Fri81.6Sat78.8Sun
Monday: 84.0 percent on time. Tuesday: 88.8 percent on time. Wednesday: 83.7 percent on time. Thursday: 77.9 percent on time. Friday: 78.7 percent on time. Saturday: 81.6 percent on time. Sunday: 78.8 percent on time

Carrier by carrier

Which airlines ran best at SAT in August

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 87.6% of the time; American Airlines manages 74.1%. Sample sizes sit next to every figure, because a two-point gap across 651 flights means less than a ten-point one.

Carriers at SAT in August 2025
AirlineFlightsOn timeAvg delayCancelledGrade
Southwest Airlines1,29484.0%53 min0.31%B+
American Airlines65174.1%105 min3.38%C−
Delta Air Lines60387.6%67 min0.50%A+
United Airlines49081.9%83 min1.63%B
Spirit Airlinesthin sample12076.5%103 min0.00%B+
SkyWest Airlinesthin sample11083.5%110 min0.00%B+
Envoy Airthin sample6869.2%126 min2.94%C
Alaska Airlinesthin sample5771.4%43 min1.75%C
Frontier Airlinesthin sample5172.0%82 min1.96%C

American Airlines cancels 3.4% 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

Busiest routes out of SAT in August

Routes from SAT in August 2025
RouteFlightsOn timeAvg delayCancelledGrade
SAT to DFW · Dallas-Fort Worth38366.8%111 min4.18%C−
SAT to ATL · Atlantathin sample26986.3%61 min0.74%A+
SAT to DEN · Denverthin sample24075.7%74 min1.67%B
SAT to DAL · Dallasthin sample21885.3%66 min0.46%A+
SAT to IAH · Houstonthin sample20879.0%68 min1.44%B
SAT to LAX · Los Angelesthin sample18292.2%74 min0.00%A+
SAT to PHX · Phoenixthin sample17482.0%91 min0.57%B+
SAT to LAS · Las Vegasthin sample16187.0%82 min0.00%A+
SAT to ORD · Chicagothin sample15473.5%75 min3.25%C−
SAT to HOU · Houstonthin sample14478.3%48 min0.00%B+
SAT to CLT · Charlottethin sample11585.1%124 min0.87%A+
SAT to DTW · Detroitthin sample9793.8%126 min0.00%A+
SAT to MSP · Minneapolisthin sample8378.0%56 min1.20%B
SAT to MCO · Orlandothin sample8272.8%57 min0.00%C+
SAT to SLC · Salt Lake Citythin sample8285.4%71 min0.00%A+
SAT to BNA · Nashvillethin sample7989.9%74 min0.00%A+
SAT to ELP · El Pasothin sample7380.8%57 min0.00%B+
SAT to BWI · Baltimorethin sample7187.0%45 min2.82%A
SAT to MDW · Chicagothin sample6085.0%59 min0.00%A+
SAT to SAN · San Diegothin sample5786.0%57 min0.00%A+
SAT to SEA · Seattlethin sample5771.4%43 min1.75%C
SAT to IAD · Washingtonthin sample5198.0%65 min0.00%A+
SAT to STL · St. Louisthin sample4791.5%21 min0.00%A+
SAT to MIA · Miamithin sample3694.3%30 min2.78%A
SAT to TPA · Tampathin sample3485.3%60 min0.00%A+

Delay causes

What held SAT up in August

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 49,000 reported delay minutes.

  • Late-arriving aircraft
    41%
  • Carrier
    31%
  • National Airspace System
    21%
  • Extreme weather
    7%

41% 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 49,000 reported delay minutes here, that single category outweighs weather by 6 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 49,316 reported delay minutes.

Cancellations sit at 1.19% against a national 1.08%, which is ordinary. Diversions add another 0.49%.

7.0% 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 last a little over an hour, which a normal layover absorbs.

What to do with this

Flying from SAT in August

For a August trip through SAT: expect 81.5% on time and 1.19% cancelled, going by August 2025. The 5am–8am window was the strongest part of the day.

Related

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.