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Route · SDF → IAD · 2020–2025 BTS data

Louisville to Washington

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SDF to IAD (Louisville to Washington) ranks #3658 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

90.9%
On-time
+11.9 pts
vs US avg
85 min
Delay when late
2,264
Flights
#3658 of 4927
Corpus placement

Cancelled

0.6%

Best Month

Oct 2024 97%

Worst Month

Aug 2024 92%

Distance

451 mi

Carriers

8

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Aug 2025 46 0 0 0 YX
Jul 2025 58 4 0 0 YX
May 2025 35 6 0 0 UA,YX
Apr 2025 50 2 0 0 YX
Mar 2025 57 2 0 0 YX
Jan 2025 31 4 4 0 YX
Dec 2024 34 6 0 0 YX
Nov 2024 60 3 0 0 YX
Oct 2024 62 2 0 0 YX
Sep 2024 60 2 0 0 YX
Aug 2024 62 5 1 0 YX
Jul 2024 62 5 0 0 YX
Jun 2024 60 2 0 0 YX
May 2024 44 8 0 0 YX,UA
Apr 2024 30 0 0 0 YX
Mar 2024 31 1 0 0 YX
Jan 2024 30 3 0 0 YX
Dec 2023 31 2 0 1 YX
Nov 2023 30 2 0 0 YX
Oct 2023 31 1 0 0 YX
Sep 2023 30 3 0 0 YX
Aug 2023 31 1 0 0 YX
Jul 2023 32 3 1 0 YX
Jun 2023 58 3 0 1 YX

SDF–IAD seasonal on-time pattern

Best: April (96.5%) · weakest: December (85.4%)

80%85%90%95%100% JanMarAprMayJunJulAugSepOctNovDec 85.4%

Strongest calendar month

April

96.5% on-time · ~33 flights/mo

Busiest calendar month

July

~50 flights/mo avg

Weakest calendar month

December

85.4% on-time · ~34 flights/mo

Cancellation Rate

0.6%

6 of 1,055 flights

Diversion Rate

0.2%

2 of 1,055 flights

Origin-hub reliability standing

Among SDF's stronger departures

SDF → IAD posts a 90.9% on-time rate, landing in the ≥85% band with 9 of 23 BTS-tracked routes leaving Louisville. The same hub also shows 13 mid-band and 1 challenged departures · fleet-wide on-time rank #98 of 4927 (highest on-time = #1).

What the Data Says About SDF to IAD

Louisville to Washington (SDF to IAD) is one of the more dependable pairings in the BTS On-Time Performance dataset: a 90.9% on-time rate across 2,264 flights, with delays that do happen averaging 85.0 minutes. The corridor runs roughly 451 miles and is served by 8 carriers. Over the most recent 24 months, 6 of 1,055 flights were cancelled (0.6%) and 2 diverted (0.2%).

Monthly on-time rates stay fairly consistent on this route, ranging from 92% in Aug 2024 to 97% in Oct 2024 - only a 5-point spread.

On the multi-year calendar, SDF–IAD peaks in April at 96.5% on-time while July carries the heaviest traffic (~50 flights per month) ; the softest month is December at 85.4%, a 11.1-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SDF to IAD rank among US routes by traffic?
According to PlainFlights' route traffic ranking, SDF to IAD ranks #3658 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from SDF to IAD?
Flights from Louisville to Washington have a 90.9% on-time rate based on 2,264 flights. The average delay is 85.0 minutes. The best recent month was Oct 2024 with 97% on-time.
What is the cancellation rate for SDF to IAD?
Over the last 24 months, 0.6% of flights on this route were cancelled (6 of 1,055 flights) and 0.2% were diverted.
How far is the flight from SDF to IAD?
The flight distance from Louisville (SDF) to Washington (IAD) is approximately 451 miles. This route is served by 8 carriers.
When is the best time to fly from SDF to IAD?
The best recent month for on-time performance was Oct 2024 (97% on-time). The worst was Aug 2024 (92% on-time). Consider booking during months with historically better performance.

Airports on this route

Data source

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

Using SDF–IAD data

SDF–IAD runs 11.9 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare SDF and IAD airport profiles: delay causes and top routes differ even on the same corridor. SDF airport
  • If your dates flex, April (96.5% on-time) beats December (85.4%) on this corridor. Seasonal chart
  • 4 other routes post a similar 90.9% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

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

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.