ON TIMEBOARD

SDF → PHL on time

Louisville Muhammad Ali (Louisville, KY) to Philadelphia (Philadelphia, PA). Every scheduled flight, September 2025 to August 2026.

On time
81%
arrived < 15 min late
Cancelled
2.4%
986 flights
Typical arrival
−14 min
median vs schedule
When late
+85 min
average delay
Flights / day
3
1 airline

81% of flights from Louisville to Philadelphia arrived on time over the past 12 months. That is about the typical U.S. route. The 7 a.m. departures ran on time 91% of the time; the 6 p.m. ones 69%. 10% 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 SDF → PHL: when a flight was late, it was under 45 minutes late 46% of the time. About 1 in 14 flights landed an hour or more late, and 1 in 70 three hours or more; 2.4% were cancelled outright.

Share of all 986 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
American Airlines98681%2.4%−14 min7.2%+85 minRepublic Airways 38%, Piedmont Airlines 36%, PSA Airlines 26%, American Airlines 1%

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 SDF). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%6 a.m. departures: too few flights (93 flights)6a7 a.m. departures: 91% on time (270 flights)917a8 a.m. departures: too few flights8a9 a.m. departures: too few flights9a10 a.m. departures: too few flights (42 flights)10a11 a.m. departures: 78% on time (171 flights)7811anoon departures: too few flights (82 flights)12p1 p.m. departures: too few flights (44 flights)1p2 p.m. departures: too few flights2p3 p.m. departures: 74% on time (116 flights)743p4 p.m. departures: too few flights (1 flights)4p5 p.m. departures: too few flights (11 flights)5p6 p.m. departures: 69% on time (142 flights)696p
SDF → PHL, 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 SDF → PHL, each airline's last flight of the day was cancelled 3.9% of the time, against 1.6% for its earlier flights (2.4× as often). It arrived 3+ hours late 1.7% of the time (earlier flights: 1.3%). 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
American Airlines6:25 p.m.3.9%1.7%1.6%first flight 7:37 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 PHL tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: October (87%). Worst: July (73%).

40%70%100%Jan: 76% on time (173 flights)76JanFeb: 74% on time (193 flights)74FebMar: 84% on time (236 flights)84MarApr: 87% on time (205 flights)87AprMay: 84% on time (236 flights)84MayJun: 81% on time (264 flights)81JunJul: 73% on time (272 flights)73JulAug: 79% on time (267 flights)79AugSep: 86% on time (275 flights)86SepOct: 87% on time (292 flights)87OctNov: 84% on time (184 flights)84NovDec: 79% on time (181 flights)79Dec

By day of week

DayFlightsOn timeCancelled
Monday15078%4.0%
Tuesday14083%2.9%
Wednesday13987%0.7%
Thursday14672%3.4%
Friday14483%1.4%
Saturday12388%1.6%
Sunday14480%2.8%

Why flights were late

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

Late inbound plane 62%Airline (crew, maintenance, ops) 26%Air traffic & airport (NAS) 11%Severe weather 1%

Cancellations: weather 16 · air traffic/airport 7 · airline 1

Month by month

Not enough months with data to draw a trend.

Flight numbers on this route

Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.

FlightDepartsFlightsOn timeCancelledTypical arrivalOperated by
AA 47507:31 a.m.20990%1.0%−16 minRepublic Airways

Worst days in the past year

DateFlightsOn timeCancelled
Oct 30, 202540%0
Aug 20, 202630%1
Jul 6, 202630%0
Mar 12, 202630%1
Aug 10, 202630%1

Questions

How often are flights from SDF to PHL on time?

81% of 986 scheduled flights from Louisville, KY to Philadelphia, PA arrived within 15 minutes of schedule between September 2025 and August 2026. 2.4% were cancelled.

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

Flights scheduled to leave at 7 a.m. were the most reliable (91% on time). The 6 p.m. departures were the least (69%).

What month has the most delays from SDF to PHL?

July (73% on time). The best month is October (87%), over 2023–2026.

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

Yes. Each airline's last SDF–PHL flight of the day was cancelled 3.9% of the time over the past year, against 1.6% 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.