ON TIMEBOARD

BWI → SDF on time

Baltimore/Washington (Baltimore, MD) to Louisville Muhammad Ali (Louisville, KY). Every scheduled flight, September 2025 to August 2026.

On time
78%
arrived < 15 min late
Cancelled
2.5%
891 flights
Typical arrival
−5 min
median vs schedule
When late
+53 min
average delay
Flights / day
2
1 airline

78% of flights from Baltimore to Louisville arrived on time over the past 12 months. That is about the typical U.S. route. The 10 a.m. departures ran on time 88% of the time; the 10 p.m. ones 62%. 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 → SDF: when a flight was late, it was under 45 minutes late 55% of the time. About 1 in 16 flights landed an hour or more late, and 1 in 297 three hours or more; 2.5% were cancelled outright.

Share of all 891 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
Southwest Airlines89178%2.5%−5 min6.4%+53 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%10 a.m. departures: 88% on time (257 flights)8810a11 a.m. departures: too few flights (96 flights)11anoon departures: too few flights12p1 p.m. departures: too few flights (12 flights)1p2 p.m. departures: too few flights (28 flights)2p3 p.m. departures: too few flights (33 flights)3p4 p.m. departures: too few flights (25 flights)4p5 p.m. departures: too few flights (59 flights)5p6 p.m. departures: too few flights (15 flights)6p7 p.m. departures: too few flights (24 flights)7p8 p.m. departures: too few flights (59 flights)8p9 p.m. departures: 70% on time (138 flights)709p10 p.m. departures: 62% on time (133 flights)6210p
BWI → SDF, 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 → SDF, each airline's last flight of the day was cancelled 4.7% of the time, against 0.9% for its earlier flights (4.9× as often). It arrived 3+ hours late 0.3% of the time (earlier flights: 0.4%). 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 Airlines9:30 p.m.4.7%0.3%0.9%first flight 10:42 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 SDF tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: February (88%). Worst: July (61%).

40%70%100%Jan: 77% on time (194 flights)77JanFeb: 88% on time (163 flights)88FebMar: 82% on time (199 flights)82MarApr: 76% on time (223 flights)76AprMay: 73% on time (240 flights)73MayJun: 73% on time (245 flights)73JunJul: 61% on time (244 flights)61JulAug: 72% on time (241 flights)72AugSep: 84% on time (239 flights)84SepOct: 78% on time (279 flights)78OctNov: 81% on time (233 flights)81NovDec: 78% on time (223 flights)78Dec

By day of week

DayFlightsOn timeCancelled
Monday13978%2.9%
Tuesday10886%2.8%
Wednesday10884%0.0%
Thursday13777%2.2%
Friday13875%1.5%
Saturday11778%4.3%
Sunday14471%3.5%

Why flights were late

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

Late inbound plane 50%Airline (crew, maintenance, ops) 36%Air traffic & airport (NAS) 12%Severe weather 2%

Cancellations: weather 12 · airline 7 · air traffic/airport 3

Month by month

Not enough months with data to draw a trend.

Worst days in the past year

DateFlightsOn timeCancelled
Aug 2, 202630%1
Jun 22, 202630%0
May 21, 202630%0
Oct 26, 2025425%0
Apr 30, 2026425%0

Nearby airport alternatives

Other ways to make the same trip, using airports within 60 miles of Baltimore or Louisville. IAD → SDF has been 4 points more reliable.

RouteFlightsOn timeCancelled
BWI → SDF (this route)89178%2.5%
IAD → SDF Washington Dulles to Louisville Muhammad Ali86782%1.0%
DCA → SDF Washington Reagan National to Louisville Muhammad Ali1,02771%5.4%

Questions

How often are flights from BWI to SDF on time?

78% of 891 scheduled flights from Baltimore, MD to Louisville, KY arrived within 15 minutes of schedule between September 2025 and August 2026. 2.5% were cancelled.

What is the best time of day to fly BWI to SDF?

Flights scheduled to leave at 10 a.m. were the most reliable (88% on time). The 10 p.m. departures were the least (62%).

What month has the most delays from BWI to SDF?

July (61% on time). The best month is February (88%), over 2023–2026.

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

Yes. Each airline's last BWI–SDF flight of the day was cancelled 4.7% of the time over the past year, against 0.9% 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.