Washington Dulles International Airport (IAD): Delays & On-Time Performance
Data through July 2026
Washington Dulles International Airport (IAD) is a tale of two seasons: departures ran 91% on-time in October 2024 but sank to 71% in July 2025. Across the year it averages 83% against a national 78%, over roughly 159 departures a day to 79 destinations.
- Departures on-time
- 83%
- left <15 min late
- Avg dep delay
- 15 min
- Arrivals on-time
- 82%
- Cancelled
- 1.3%
- Destinations
- 79
- nonstop
- Airlines
- 11
Plan your departure from IAD
The choices most likely to improve your odds, based on this airport’s historical record.
- Best departure time
- Around 6 a.m.
- 91% on-time
- Best day to fly
- Tuesday
- 83% on-time
- Cancellation risk
- 1.3%
- below the US average
Monthly on-time trend
Best time of day to depart from IAD
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 80% | 17 min |
| Tuesdaybest | 83% | 13 min |
| Wednesday | 81% | 15 min |
| Thursday | 79% | 17 min |
| Friday | 79% | 18 min |
| Saturday | 81% | 16 min |
| Sunday | 78% | 19 min |
Busiest routes from IAD
Where flights into IAD come from
| Route | Flights/12mo | On-time | Avg delay |
|---|---|---|---|
| ATL (Atlanta) → IAD | 3,992 | 76% | 20 min |
| DEN (Denver) → IAD | 3,463 | 80% | 14 min |
| SFO (San Francisco) → IAD | 2,730 | 83% | 12 min |
| LAX (Los Angeles) → IAD | 2,474 | 86% | 8 min |
| MCO (Orlando) → IAD | 2,178 | 80% | 17 min |
| ORD (Chicago) → IAD | 2,082 | 76% | 19 min |
| CLT (Charlotte) → IAD | 1,990 | 80% | 16 min |
| DFW (Dallas/Fort Worth) → IAD | 1,952 | 77% | 18 min |
What causes delays at IAD
Share of total delay minutes by cause, as reported by carriers to the US DOT, weighted across routes departing IAD.
- Late-arriving aircraft33%
- Airline operations32%
- National airspace system26%
- Weather10%
Alternative airports near Washington
Other airports within 120 miles, compared on departure reliability.
| Airport | Distance | On-time departures | Avg delay |
|---|---|---|---|
| DCA — Ronald Reagan Washington National Airport | 23 mi | 75% | 21 min |
| BWI — Baltimore/Washington International Thurgood Marshall Airport | 45 mi | 73% | 17 min |
| CHO — Charlottesville Albemarle Airport | 77 mi | 80% | 23 min |
| MDT — Harrisburg International Airport | 94 mi | 79% | 21 min |
| RIC — Richmond International Airport | 100 mi | 79% | 17 min |
Compare the airport-level record first, then check the exact route you plan to book.
Airline performance at IAD
| Airline | On-time departures | Avg delay | Flights |
|---|---|---|---|
| Endeavor Air | 90% | 8 min | 151 |
| Republic Airways | 85% | 13 min | 18,536 |
| United Airlines | 84% | 14 min | 73,679 |
| PSA Airlines | 81% | 19 min | 2,749 |
| Delta Air Lines | 80% | 19 min | 6,454 |
| SkyWest Airlines | 80% | 27 min | 5,603 |
| Alaska Airlines | 77% | 14 min | 3,450 |
| American Airlines | 76% | 24 min | 2,336 |
| Southwest Airlines | 75% | 14 min | 2,354 |
| Allegiant Air | 73% | 32 min | 970 |
| Frontier Airlines | 70% | 31 min | 2,556 |
Frequently asked questions
- How often are flights delayed at IAD?
- 17% of departures from Washington Dulles International Airport left 15+ minutes late between 2024-07 and 2026-07, with an average departure delay of 15 minutes. The national on-time average over the same period was 78%.
- What is the best time of day to depart from IAD?
- Flights scheduled around 6 a.m. depart on time 91% of the time at IAD, versus 61% around 9 p.m.. Booking before noon is the usual rule of thumb here.
- What is the worst month for delays at IAD?
- In this dataset, July 2025 was the weakest month at IAD, with 71% of departures on time.
- How often are flights cancelled at IAD?
- 1.3% of scheduled departures from IAD were cancelled in this period, compared with a national rate of 1.6%.
Popular route pages from this airport
Related guides
Based on 118,838 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.