ON TIMEBOARD

PHL → SDF on time

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

On time
79%
arrived < 15 min late
Cancelled
2.7%
987 flights
Typical arrival
−10 min
median vs schedule
When late
+76 min
average delay
Flights / day
3
1 airline

79% of flights from Philadelphia to Louisville arrived on time over the past 12 months. That is about the typical U.S. route. The 7 p.m. departures ran on time 87% of the time; the 3 p.m. ones 69%. 11% 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 PHL → SDF: when a flight was late, it was under 45 minutes late 44% of the time. About 1 in 13 flights landed an hour or more late, and 1 in 110 three hours or more; 2.7% were cancelled outright.

Share of all 987 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
American Airlines98779%2.7%−10 min7.8%+76 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 PHL). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%8 a.m. departures: 79% on time (177 flights)798a9 a.m. departures: 81% on time (117 flights)819a10 a.m. departures: too few flights (46 flights)10a11 a.m. departures: too few flights (1 flights)11anoon departures: too few flights (89 flights)12p1 p.m. departures: too few flights (38 flights)1p2 p.m. departures: too few flights (1 flights)2p3 p.m. departures: 69% on time (142 flights)693p4 p.m. departures: too few flights (14 flights)4p5 p.m. departures: too few flights5p6 p.m. departures: 82% on time (111 flights)826p7 p.m. departures: 87% on time (104 flights)877p8 p.m. departures: 75% on time (145 flights)758p
PHL → 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 PHL → SDF, each airline's last flight of the day was cancelled 4.4% of the time, against 1.8% for its earlier flights (2.5× as often). It arrived 3+ hours late 0.6% 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 Airlines8:40 p.m.4.4%0.6%1.8%first flight 9:31 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: September (88%). Worst: July (69%).

40%70%100%Jan: 78% on time (173 flights)78JanFeb: 79% on time (193 flights)79FebMar: 86% on time (236 flights)86MarApr: 86% on time (203 flights)86AprMay: 78% on time (239 flights)78MayJun: 77% on time (265 flights)77JunJul: 69% on time (273 flights)69JulAug: 74% on time (267 flights)74AugSep: 88% on time (274 flights)88SepOct: 87% on time (292 flights)87OctNov: 88% on time (185 flights)88NovDec: 81% on time (181 flights)81Dec

By day of week

DayFlightsOn timeCancelled
Monday14983%3.4%
Tuesday14177%4.3%
Wednesday13984%1.4%
Thursday14473%2.1%
Friday14478%2.8%
Saturday12485%2.4%
Sunday14675%2.7%

Why flights were late

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

Late inbound plane 53%Air traffic & airport (NAS) 21%Airline (crew, maintenance, ops) 17%Severe weather 9%

Cancellations: weather 18 · air traffic/airport 7 · airline 2

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 44668:40 p.m.18082%3.3%−18 minRepublic Airways

Worst days in the past year

DateFlightsOn timeCancelled
Oct 30, 202540%0
Jul 28, 202630%2
Jul 22, 202630%0
Mar 8, 202630%0
Jul 21, 202630%3

Questions

How often are flights from PHL to SDF on time?

79% of 987 scheduled flights from Philadelphia, PA to Louisville, KY arrived within 15 minutes of schedule between September 2025 and August 2026. 2.7% were cancelled.

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

Flights scheduled to leave at 7 p.m. were the most reliable (87% on time). The 3 p.m. departures were the least (69%).

What month has the most delays from PHL to SDF?

July (69% on time). The best month is September (88%), over 2023–2026.

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

Yes. Each airline's last PHL–SDF flight of the day was cancelled 4.4% of the time over the past year, against 1.8% 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.