IAD to MIA flight delays & on-time performance
Nonstop flights from Washington Dulles International Airport to Miami International Airport · 922 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at IAD or MIA right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Washington (IAD) to Miami (MIA) arrived on time 83% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 0.8% were cancelled, and 5% arrived an hour or more late.
- United Airlines was the most punctual airline here (86% on time); Frontier Airlines was the least (69%).
- Departures scheduled around 8am did best (88% on time); around 3pm did worst (78%).
- Wednesday was the most reliable day to fly (90% on time) and Thursday the least (77%).
- The largest source of delay minutes was air traffic control & airport congestion (46%).
Which airline is most on time from IAD to MIA?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| United Airlines | 86% | 0.6% | 10 min | 4.1% | 512 |
| Frontier Airlines | 69% | 1.8% | 21 min | 7.2% | 113 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 8am88%340 flights
- 9am84%19 flights
- 1pm83%140 flights
- 3pm78%41 flights
- 4pm75%12 flights
- 5pm69%13 flights
- 8pm92%12 flights
- 10pm78%10 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday82%1.9% cancelled
- Tuesday86%0.0% cancelled
- Wednesday90%0.0% cancelled
- Thursday77%1.1% cancelled
- Friday83%0.0% cancelled
- Saturday88%0.0% cancelled
- Sunday78%2.1% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Air traffic control & airport congestion46%
- Late-arriving aircraft27%
- Airline (crew, maintenance, cleaning, fueling)26%
- Extreme weather1%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)80%
- Extreme weather20%
- Air traffic control & airport congestion0%
- Security0%
IAD to MIA: common questions
- How often are IAD to MIA flights on time?
- 83% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Washington to Miami cancelled?
- 0.8% of scheduled flights were cancelled (5 of 625).
- How long are typical delays?
- Across all flights the average arrival delay was 12 min (early arrivals count as zero). Flights that were late arrived 66 min behind schedule on average, and 4.7% of flights were an hour or more late.
- How long is taxi time at IAD?
- Flights on this route spent 22 min taxiing from the gate to takeoff on average.
Related routes
Return trip: MIA to IAD — 83% on time
More flights from Washington
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: IAD → MIA, nonstop flights by US airlines that report to the DOT. How we calculate this.