Route reliability record
DTW→SDF
Detroit to Louisville
- Flights
- 1,089
- Period
- September 2025 to August 2026
- Distance
- 306 mi
- Carriers
- 3
This route lands a B, level with the national rate of 77.3%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That rests on 1,089 DTW to SDF flights, of which SkyWest Airlines flew 670 at 78.0% on time.
Best time to fly DTW to SDF: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 82.8% of the time and Saturday flights 83.9%, against 77.5% for the route overall.
The US average over the same twelve months is 77.3%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.5%
Arrivals under 15 minutes late, of 1,072 completed flights
Avg delay
87 min
Across delayed arrivals only, not all flights
Cancelled
1.47%
National rate is 1.89%
Best carrier
SkyWest
78.0% on time across 670 flights
These figures cover 1,089 flights between September 2025 and August 2026. Beyond the headline rate, 10.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Which airline is most reliable on DTW to SDF
The two carriers here are closely matched: half a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 670 | 78.0% | 85 min | 1.64% | B |
| Republic Airways | 408 | 77.6% | 90 min | 1.23% | B |
| Delta Air Linesthin sample | 11 | 45.5% | 88 min | 0.00% | F+ |
No carrier stands out. SkyWest tops the table at 78.0%, half a point clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
Flights on DTW to SDF
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Best ways to make this trip
The most reliable ways to fly Detroit to Louisville
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. DTW → SDFDetroit to Louisville | SkyWest Airlines | 76.7% | 78.0% | 1.64% | 8am–11am, Sat | — |
| 2. DTW → SDFDetroit to Louisville | Republic Airways | 76.6% | 77.6% | 1.23% | 2pm–5pm, Thu | YX 5832 19:45 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am349 flights82.8%
- 11am–2pm189 flights78.0%
- 2pm–5pm176 flights69.4%
- 5pm–8pm164 flights76.4%
- 8pm–5am211 flights76.0%
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 82.8% of the time, against 69.4% for the afternoon window. That is 13 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 349 flights scheduled in it.
Explore
Filter DTW to SDF by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On DTW to SDF, the best departure window is 8am–11am at 82.8% on time and the worst is 2pm–5pm at 69.4%, a wide gap of 13.4 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am—
- 8–11am82.8%
- 11am–2pm78.0%
- 2–5pm69.4%
- 5–8pm76.4%
- 8pm–5am76.0%
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 34 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
December is the weak month at 61.6% on time, against 95.9% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. May was the busiest month here, with 118 flights.
Across the week, Saturday is the strongest day at 83.9% on time and Friday the weakest at 69.3%, a spread of 15 points.
Delay causes
Why this route gets delayed
Carrier accounts for 53% of the 21,000 delay minutes carriers reported here, and the remaining four split what is left.
- 53%Carrier
- 20%Late-arriving aircraft
- 18%Extreme weather
- 10%National Airspace System
Extreme weather accounts for 18% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.0 times the usual weather exposure. The split is drawn from 20,925 reported delay minutes.
The largest share of delay minutes, 53%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 11,000 of the 21,000 delay minutes reported here.
Cancellations sit at 1.47% against a national 1.89%, which is ordinary. Diversions add another 0.09%.
Connections and stage length
What a delay here actually costs
10.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 306 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 82.7% on time across 1,089 flights, 5 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.
One caution: this is a thin sample. 1,089 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
Work out the risk of missing a connection in SDF after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 1,089 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 77.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,072 completed flights over 12 months sit behind that.
Common questions
DTW to SDF questions
How often is DTW to SDF delayed?
Roughly one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 22.5% of the 1,089 flights in this analysis, against 22.7% nationally. Delayed flights are late by an hour and a half on average.
Which airline is most reliable on DTW to SDF?
SkyWest Airlines leads at 78.0% on time across 670 flights. Republic Airways is at the other end on 77.6%, a gap of half a point. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on DTW to SDF?
The 8am–11am departure window is the strongest at 82.8% on time. The 2pm–5pm window is the weakest at 69.4%, 13 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are December delays on DTW to SDF?
December is the weakest month at 61.6% on time, compared with 95.9% in September. Across the year that is 34 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- SDF to DTW — the return legseparate record
- Detroit Metropolitan Wayne County (DTW) delay statistics
- SkyWest Airlines on DTW to SDF78.0%
- Republic Airways on DTW to SDF77.6%
- DTW to ORD, a related route72.2%
- ORD to SDF, a related route75.8%
- DTW to ATL, a related route78.9%
- SkyWest Airlines on-time record78.0%
- Republic Airways on-time record77.6%
- Delta Air Lines on-time record45.5%
- How often a connection fails at the major US hubs
- The best time of day to fly, according to 7.05 million flight records
Direction matters. DTW to SDF and SDF to DTW are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Embed DTW to SDF’s on-time badge on your site
Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.