Dulles (IAD) to Louisville (SDF) flights
Republic Airline, Mesa Airlines fly nonstop from Washington Dulles International Airport to Louisville Muhammad Ali International Airport, with about 20 flights a week in July 2026. The 451-mile flight takes about 1h 47m gate to gate.
- Distance
- 451 mi · 726 km
- Flight time
- 1h 47m
- Airlines
- 2
- Seats filled
- 75%
Airlines flying IAD to SDF
| Airline | Flights a week | Aircraft | Passengers (12 months) | Flight time |
|---|---|---|---|---|
| Republic Airline | 13 | Embraer E175, Embraer E170 | 12,226 | 1h 45m |
| Mesa Airlines | 7 | Embraer E175 | 36,775 | 1h 48m |
Airlines are the operating carrier: regional airlines such as SkyWest or Horizon often fly under a larger airline's brand.
IAD to SDF flight schedule
5 flight numbers flew this route in August 2026, 2 of them almost daily. The first usually leaves at 8:31am and the last at 5:25pm. Times are local and can change; check with the airline before you book.
| Flight | Departs | Arrives | Days flown in August 2026 | On time (12 months) |
|---|---|---|---|---|
| UA 3526United Airlines · operated by Republic Airline | 8:31am | 10:23am | 10 | 90% |
| UA 3525United Airlines · operated by Republic Airline | 8:35am | 10:18am | 15 | 87% |
| UA 3980United Airlines · operated by Mesa Airlines | 12:50pm | 2:37pm | 30 | 82% |
| UA 3538United Airlines · operated by Republic Airline | 5:25pm | 7:18pm | 10 | 80% |
| UA 3570United Airlines · operated by Republic Airline | 5:25pm | 7:15pm | 21 | 62% |
Is IAD to SDF on time?
From September 2025 to August 2026, 83% of 867 flights arrived within 15 minutes of schedule and 1% were cancelled. Flights leaving around 8am were the most punctual (89%), those around 7pm the least (80%). Most delay time was caused by late-arriving aircraft (41%).
| Airline | Flights | On time | Average delay | Cancelled |
|---|---|---|---|---|
| United Airlines | 867 | 83% | 17 min | 1% |
Airlines as sold: flights operated by regional partners count under the airline on the ticket. Average delay is across all completed flights, early arrivals counted as zero.
On-time arrivals by departure time
| Scheduled departure | Flights | On time, relative | On time |
|---|---|---|---|
| 8am to 9am | 96 | 89% | |
| 12pm to 1pm | 306 | 81% | |
| 1pm to 2pm | 55 | 89% | |
| 3pm to 4pm | 24 | 100% | |
| 5pm to 6pm | 294 | 82% | |
| 7pm to 8pm | 55 | 80% | |
| 10pm to 11pm | 21 | 71% |
Flights by month
| Month | Flights | Flights, relative | Passengers |
|---|---|---|---|
| August 2025 | 107 | 4,891 | |
| September 2025 | 84 | 4,566 | |
| October 2025 | 62 | 3,834 | |
| November 2025 | 59 | 3,391 | |
| December 2025 | 62 | 3,343 | |
| January 2026 | 59 | 3,002 | |
| February 2026 | 54 | 3,153 | |
| March 2026 | 62 | 3,634 | |
| April 2026 | 61 | 3,678 | |
| May 2026 | 92 | 4,508 | |
| June 2026 | 91 | 5,628 | |
| July 2026 | 90 | 5,729 |
Related
Source: US Department of Transportation, T-100 Segment data, August 2025 to July 2026.