ON TIMEBOARD

BWI → SAT on time

Baltimore/Washington (Baltimore, MD) to San Antonio (San Antonio, TX). Every scheduled flight, September 2025 to August 2026.

On time
73%
arrived < 15 min late
Cancelled
1.6%
731 flights
Typical arrival
−3 min
median vs schedule
When late
+57 min
average delay
Flights / day
2
1 airline

73% of flights from Baltimore to San Antonio arrived on time over the past 12 months. That is worse than the typical U.S. route. 9% of flights arrived more than an hour late or not at all.

How late?

The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for BWI → SAT: when a flight was late, it was under 45 minutes late 58% of the time. About 1 in 14 flights landed an hour or more late, and 1 in 91 three hours or more; 1.6% were cancelled outright.

Share of all 731 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
Southwest Airlines73173%1.6%−3 min7.3%+57 minSouthwest Airlines

Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.

Best time of day to fly

On-time rate by scheduled departure hour (local time at BWI). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%8 a.m. departures: 88% on time (117 flights)888a9 a.m. departures: too few flights (78 flights)9a10 a.m. departures: too few flights (77 flights)10a11 a.m. departures: too few flights (10 flights)11anoon departures: too few flights (13 flights)12p1 p.m. departures: too few flights (45 flights)1p2 p.m. departures: too few flights (30 flights)2p3 p.m. departures: too few flights (53 flights)3p4 p.m. departures: too few flights4p5 p.m. departures: too few flights (29 flights)5p6 p.m. departures: too few flights (82 flights)6p7 p.m. departures: too few flights (73 flights)7p8 p.m. departures: too few flights (98 flights)8p
BWI → SAT, share of flights arriving on time, by departure hour. Hours with under 100 flights are greyed out.
82%+ on time76–82%68–76%under 68%too few flights

Last flight of the day

On BWI → SAT, each airline's last flight of the day was cancelled 2.6% of the time, against 0.5% for its earlier flights (4.8× as often). It arrived 3+ hours late 1.1% of the time (earlier flights: 1.1%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.

AirlineLast departureLast: cancelledLast: 3h+ lateEarlier: cancelledNext morning
Southwest Airlines7:05 p.m.2.6%1.1%0.5%first flight 9:25 a.m.

Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.

If you need to be in SAT tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: November (83%). Worst: July (60%).

40%70%100%Jan: 68% on time (160 flights)68JanFeb: 80% on time (147 flights)80FebMar: 79% on time (170 flights)79MarApr: 74% on time (165 flights)74AprMay: 62% on time (173 flights)62MayJun: 60% on time (232 flights)60JunJul: 60% on time (239 flights)60JulAug: 75% on time (216 flights)75AugSep: 82% on time (236 flights)82SepOct: 81% on time (262 flights)81OctNov: 83% on time (216 flights)83NovDec: 75% on time (212 flights)75Dec

By day of week

DayFlightsOn timeCancelled
Monday12472%3.2%
Tuesday10680%1.9%
Wednesday10481%0.0%
Thursday11977%0.8%
Friday12373%0.8%
Saturday67——
Sunday88——

Why flights were late

Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.

Late inbound plane 47%Airline (crew, maintenance, ops) 31%Air traffic & airport (NAS) 18%Severe weather 3%Security 1%

Cancellations: weather 9 · airline 3

Month by month

Not enough months with data to draw a trend.

Worst days in the past year

DateFlightsOn timeCancelled
Dec 27, 202530%1
Aug 28, 202630%0
Jun 15, 202630%0
Jun 17, 202630%0
Jul 28, 202630%1

Nearby airport alternatives

Other ways to make the same trip, using airports within 60 miles of Baltimore or San Antonio. IAD → SAT has been 12 points more reliable.

RouteFlightsOn timeCancelled
BWI → SAT (this route)73173%1.6%
IAD → SAT Washington Dulles to San Antonio68885%0.6%

Questions

How often are flights from BWI to SAT on time?

73% of 731 scheduled flights from Baltimore, MD to San Antonio, TX arrived within 15 minutes of schedule between September 2025 and August 2026. 1.6% were cancelled.

What month has the most delays from BWI to SAT?

July (60% on time). The best month is November (83%), over 2023–2026.

Is the last flight of the day from BWI to SAT more likely to be cancelled?

Yes. Each airline's last BWI–SAT flight of the day was cancelled 2.6% of the time over the past year, against 0.5% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.

Related

Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.