76% of flights from Detroit to Louisville arrived on time over the past 12 months. That is worse than the typical U.S. route. The 8 a.m. departures ran on time 82% of the time; the 3 p.m. ones 68%. 12% 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 DTW → SDF: when a flight was late, it was under 45 minutes late 44% of the time. About 1 in 10 flights landed an hour or more late, and 1 in 44 three hours or more; 1.3% were cancelled outright.
- On time or early76%
- 15–30 min late6.0%
- 30–60 min late6.9%
- 1–2 hours late5.7%
- 2–3 hours late2.2%
- 3+ hours late2.3%
- Diverted0.1%
- Cancelled1.3%
Share of all 1,306 scheduled flights, past 12 months, by arrival time against schedule.
By airline
| Airline | Flights | On time | Cancelled | Typical arrival | 1h+ late | Avg when late | Operated by |
|---|---|---|---|---|---|---|---|
| Delta Air Lines | 1,306 | 76% | 1.3% | −8 min | 10.2% | +87 min | SkyWest 51%, Republic Airways 31%, Endeavor Air 17%, Delta Air Lines 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 DTW). Delays build through the day as late planes knock on, so early flights usually do best.
Last flight of the day
On DTW → SDF, each airline's last flight of the day was cancelled 1.4% of the time, against 1.3% for its earlier flights, about the same. It arrived 3+ hours late 2.7% of the time (earlier flights: 2.1%). 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.
| Airline | Last departure | Last: cancelled | Last: 3h+ late | Earlier: cancelled | Next morning |
|---|---|---|---|---|---|
| Delta Air Lines | 7:45 p.m. | 1.4% | 2.7% | 1.3% | first flight 8:25 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.
By month
Each calendar month pooled over 2023–2026. Best: October (92%). Worst: January (68%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 196 | 74% | 1.0% |
| Tuesday | 193 | 78% | 0.5% |
| Wednesday | 191 | 79% | 1.1% |
| Thursday | 191 | 72% | 0.5% |
| Friday | 188 | 70% | 1.6% |
| Saturday | 155 | 83% | 1.9% |
| Sunday | 192 | 75% | 2.6% |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: weather 8 · airline 6 · air traffic/airport 3
Month by month
Flight numbers on this route
Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.
| Flight | Departs | Flights | On time | Cancelled | Typical arrival | Operated by |
|---|---|---|---|---|---|---|
| DL 3821 | 8:25 a.m. | 170 | 84% | 1.2% | −12 min | SkyWest |
| DL 5832 | 7:45 p.m. | 364 | 74% | 1.4% | −8 min | Republic Airways |
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Mar 13, 2026 | 4 | 0% | 0 |
| Dec 19, 2025 | 4 | 0% | 0 |
| Nov 9, 2025 | 4 | 0% | 0 |
| Dec 7, 2025 | 4 | 0% | 0 |
| Jan 27, 2026 | 3 | 0% | 1 |
Questions
How often are flights from DTW to SDF on time?
76% of 1,306 scheduled flights from Detroit, MI to Louisville, KY arrived within 15 minutes of schedule between September 2025 and August 2026. 1.3% were cancelled.
What is the best time of day to fly DTW to SDF?
Flights scheduled to leave at 8 a.m. were the most reliable (82% on time). The 3 p.m. departures were the least (68%).
What month has the most delays from DTW to SDF?
January (68% on time). The best month is October (92%), over 2023–2026.
Is the last flight of the day from DTW to SDF more likely to be cancelled?
Not much. Each airline's last DTW–SDF flight of the day was cancelled 1.4% of the time over the past year, against 1.3% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- SDF → DTW (return)
- Detroit Metro (DTW) delays by hour
- Flights into Louisville Muhammad Ali (SDF)
- Delta Air Lines on-time record
- Connecting off this flight? Check the risk
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.