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Route · IAD → SDF · 2020–2025 BTS data

Washington to Louisville

The IAD–SDF corridor (Washington, DC → Louisville, KY) runs ahead of the national average, served by 8 carriers across roughly 451 miles.

Data updated 2026-06-13

85.1%
On-time
+6.1 pts
vs US avg
101 min
Delay when late
2,295
Flights

Cancelled

1.0%

Best Month

Oct 2024 95%

Worst Month

Jul 2025 78%

Distance

451 mi

Carriers

8

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Aug 2025 46 4 0 0 YX
Jul 2025 58 13 0 0 YX
Jun 2025 30 9 0 0 YX
May 2025 34 2 0 0 UA,YX
Apr 2025 50 4 0 0 YX
Mar 2025 57 6 0 0 YX
Jan 2025 31 3 3 0 YX
Dec 2024 33 2 0 0 YX
Nov 2024 60 5 0 0 YX
Oct 2024 61 3 0 0 YX
Sep 2024 60 3 0 0 YX
Aug 2024 62 11 3 0 YX
Jul 2024 62 10 0 0 YX
Jun 2024 60 6 0 0 YX
May 2024 45 5 0 0 YX,UA
Apr 2024 30 5 0 0 YX
Mar 2024 31 3 0 0 YX
Jan 2024 31 6 0 0 YX
Dec 2023 31 3 0 0 YX
Nov 2023 30 0 0 0 YX
Oct 2023 31 5 0 0 YX
Sep 2023 31 5 2 0 YX
Aug 2023 31 3 1 0 YX
Jul 2023 32 11 1 0 YX

Cancellation Rate

1.0%

10 of 1,027 flights

Diversion Rate

0.0%

0 of 1,027 flights

What the Data Says About IAD to SDF

Washington to Louisville (IAD to SDF) is one of the more dependable pairings in the BTS On-Time Performance dataset: a 85.1% on-time rate across 2,295 flights, with delays that do happen averaging 101.3 minutes. The corridor runs roughly 451 miles and is served by 8 carriers. Over the most recent 24 months, 10 of 1,027 flights were cancelled (1.0%) and 0 diverted (0.0%).

The monthly split is wide on this route: Oct 2024 posted the strongest performance at 95% on-time, while Jul 2025 came in at just 78% - a 18-point swing worth factoring into travel timing.

Frequently Asked Questions

How often are flights delayed from IAD to SDF?
Flights from Washington to Louisville have a 85.1% on-time rate based on 2,295 flights. The average delay is 101.3 minutes. The best recent month was Oct 2024 with 95% on-time.
What is the cancellation rate for IAD to SDF?
Over the last 24 months, 1.0% of flights on this route were cancelled (10 of 1,027 flights) and 0.0% were diverted.
How far is the flight from IAD to SDF?
The flight distance from Washington (IAD) to Louisville (SDF) is approximately 451 miles. This route is served by 8 carriers.
When is the best time to fly from IAD to SDF?
The best recent month for on-time performance was Oct 2024 (95% on-time). The worst was Jul 2025 (78% on-time). Consider booking during months with historically better performance.

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Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights Editorial

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.