Route reliability record
MIA→DCA
Miami to Washington
- Flights
- 3,962
- Period
- July 2025 to June 2026
- Distance
- 919 mi
- Carriers
- 4
This route sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 3,962 flights, with a median arrival 5 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.7%
Arrivals under 15 minutes late, of 3,859 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
2.15%
National rate is 1.81%
Best carrier
American
74.8% on time across 3,549 flights
These figures cover 3,962 flights between July 2025 and June 2026. Beyond the headline rate, 9.3% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on MIA to DCA
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Airthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Delta Air Linesthin sample | 364 | 75.2% | 75 min | 1.10% | B |
| American Airlines | 3,549 | 74.8% | 70 min | 2.28% | C |
| Republic Airwaysthin sample | 48 | 66.7% | 76 min | 0.00% | C+ |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am361 flights88.8%
- 8am–11am728 flights87.3%
- 11am–2pm757 flights76.6%
- 2pm–5pm681 flights65.3%
- 5pm–8pm715 flights62.2%
- 8pm–5am720 flights73.7%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 62.2% on time, against 88.8% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 11am–2pm window is the busiest, with 757 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 22 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 58.4% on time, 22 points below May, the best at 80.6%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. December was the busiest month here, with 344 flights.
Across the week, Tuesday is the strongest day at 79.9% on time and Friday the weakest at 71.2%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 68,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 43%Late-arriving aircraft
- 32%Carrier
- 19%National Airspace System
- 5%Extreme weather
- 0%Security
43% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 68,000 reported delay minutes here, that single category outweighs weather by 9 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 68,404 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 88.8% on time here.
Cancellations sit at 2.15% against a national 1.81%, which is ordinary. Diversions add another 0.45%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.3% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 919 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg runs 76.2% on time across 3,959 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 3,962 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. May runs 80.6% on time and July 58.4%, a swing of 22 points. If the dates move at all, move them out of July before you think about anything else. 3,859 completed flights over 12 months sit behind that.
Common questions
MIA to DCA questions
How often is MIA to DCA delayed?
About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.3% of the 3,962 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is MIA to DCA compared with the rest of the country?
74.7% of flights arrive on time here against a national 77.6%, a difference of 3 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on MIA to DCA?
The 5am–8am departure window is the strongest at 88.8% on time. The 5pm–8pm window is the weakest at 62.2%, 27 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on MIA to DCA?
July is the weakest month at 58.4% on time, compared with 80.6% in May. Across the year that is 22 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- DCA to MIA — the return legseparate record
- Miami International (MIA) delay statistics
- Ronald Reagan Washington National (DCA) delay statistics
- Envoy Air on-time record100.0%
- Delta Air Lines on-time record75.2%
- American Airlines on-time record74.8%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. MIA to DCA and DCA to MIA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.