Carrier route record
DLMIA→DCA
Delta Air Lines · Miami to Washington
- Flights
- 363
- Period
- September 2025 to August 2026
- Share of route
- 9%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on MIA to DCA lands a B+, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 363 flights, with a median arrival 7 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Delta on MIA to DCA from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.9%
Arrivals under 15 minutes late, of 360 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
Whole route
75.9%
Every carrier on MIA to DCA, 3,954 flights
These figures cover 363 flights between September 2025 and August 2026. Beyond the headline rate, 8.9% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Delta against every carrier on MIA to DCA
Delta flew 363 of the 3,954 flights on MIA to DCA, about 9% of it. Its 78.9% on time is 3 points better than the route as a whole, which runs 75.9%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from Envoy at 100.0% to Republic at 65.7%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 Lines (this page)thin sample | 363 | 78.9% | 73 min | 0.55% | B+ |
| American Airlines | 3,555 | 75.7% | 69 min | 2.22% | B |
| Republic Airwaysthin sample | 35 | 65.7% | 81 min | 0.00% | C+ |
Flight by flight
Delta flight numbers on MIA to DCA
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Departure window
When Delta runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 363 flights.
There are not enough flights in each departure window to split Delta's MIA to DCA record by time of day without the percentages moving on noise. The headline rate of 78.9% is the reliable figure here.
Across the year
Delta on MIA to DCA through the year
October is the best month on the calendar at 96.8% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. January was the busiest month here, with 31 flights.
Across the week, Tuesday is the strongest day at 82.7% on time and Friday the weakest at 75.0%, a spread of 8 points.
Arrival by arrival
How late Delta on MIA to DCA runs when it is late
Delta on MIA to DCA often beats the schedule: 105 of 360 completed flights, 29%, arrived 15 minutes or more early. The 76 late arrivals split 22 under half an hour, 22 between 30 and 60 minutes, and 32 an hour or more.
- 15+ min early105 flights29.2%
- Within 15 min179 flights49.7%
- 15–29 min late22 flights6.1%
- 30–59 min late22 flights6.1%
- 1–2 hours late20 flights5.6%
- 2+ hours late12 flights3.3%
Scale runs 0% to 100%.
Share of 360 completed flights by arrival against schedule.
12 of 69 late departures made up the time and arrived on time, 17% of them. In the other direction, 19 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at DCA.
The worst days
Worst days for Delta on MIA to DCA
The latest arrival of the period was on 29 January 2026, 5 hours 5 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 29 January 2026 | 5 hours 5 minutes | Late-arriving aircraft |
| 20 January 2026 | 4 hours 18 minutes | Late-arriving aircraft |
| 2 February 2026 | 4 hours 12 minutes | Carrier |
| 14 July 2026 | 4 hours 2 minutes | National Airspace System |
| 12 June 2026 | 3 hours 59 minutes | Late-arriving aircraft |
Delay causes
Why Delta runs late on this route
Late-arriving aircraft accounts for 60% of the 5,515 delay minutes carriers reported here, and the remaining four split what is left.
- 60%Late-arriving aircraft
- 23%National Airspace System
- 14%Carrier
- 2%Extreme weather
60% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 5,515 reported delay minutes here, that single category outweighs weather by 25 to one. The split is drawn from 5,515 reported delay minutes.
Cancellations are rare at 0.55%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
8.9% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
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.
The return leg is a different operation and performs like one: it runs 70.9% on time across 363 flights, 8 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 8 points of difference.
One caution: this is a thin sample. 363 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Delta on MIA to DCA
Put together: treat all of this as provisional. 363 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 78.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 360 completed flights over 12 months sit behind that.
Related
Where to go next
- MIA to DCA, every carrier
- Delta on DCA to MIA, the return leg
- American Airlines on MIA to DCA75.7%
- Delta Air Lines network-wide record
- Miami International (MIA) delay statistics
- Ronald Reagan Washington National (DCA) delay statistics
- Why the first flight of the morning is statistically safest
- Worst months to fly in the US, ranked by the data
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.