Carrier route record

DLDCA→MIA

Delta Air Lines · Washington to Miami

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 DCA to MIA sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.3%. The late ones land a little over an hour behind schedule. That rests on 363 flights, with a median arrival 4 minutes early.

The national on-time rate over the same period is 77.3%, so Delta on DCA to MIA runs 6 points behind the country as a whole. Across a thousand flights that is about 64 extra late arrivals.

On time

70.9%

Arrivals under 15 minutes late, of 354 completed flights

Avg delay

75 min

Across delayed arrivals only, not all flights

Cancelled

0.83%

National rate is 1.89%

Whole route

76.9%

Every carrier on DCA to MIA, 3,954 flights

These figures cover 363 flights between September 2025 and August 2026. Beyond the headline rate, 11.3% 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 DCA to MIA

Delta flew 363 of the 3,954 flights on DCA to MIA, about 9% of it. Its 70.9% on time is 6 points worse than the route as a whole, which runs 76.9%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from Envoy at 100.0% to Republic at 57.1%. 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.

On-time performance by carrier on DCA to MIA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Envoy Airthin sample	1	100.0%	—	0.00%	A+
American Airlines	3,555	77.7%	76 min	2.28%	B
Delta Air Lines (this page)thin sample	363	70.9%	75 min	0.83%	C+
Republic Airwaysthin sample	35	57.1%	75 min	0.00%	D+

Flight by flight

Delta flight numbers on DCA to MIA

DL 257614:0069.3% · 332 flights

Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

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.

5am–8am—
8am–11am—
11am–2pm36 flights77.1%
2pm–5pm327 flights70.2%
5pm–8pm—
8pm–5am—

Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 11am–2pm slot at 77.1% on time, ahead of 2pm–5pm at 70.2%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 2pm–5pm window is the busiest, with 327 flights scheduled in it.

Across the year

Delta on DCA to MIA through the year

Jul–Sep 202530 flights—
Oct–Dec 202591 flights67.0%
Jan–Mar 202690 flights75.0%
Apr–Jun 202691 flights71.8%
Jul–Sep 202661 flights70.5%

Scale runs 60% to 80%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 70.9% on time across 363 flights.

Quarter by quarter Delta on DCA to MIA held fairly steady: 67.0% in Oct–Dec 2025, 75.0% in Jan–Mar 2026, 71.8% in Apr–Jun 2026 and 70.5% in Jul–Sep 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Thursday is the strongest day at 82.0% on time and Sunday the weakest at 59.2%, a spread of 23 points.

Arrival by arrival

How late Delta on DCA to MIA runs when it is late

Delta on DCA to MIA often beats the schedule: 121 of 354 completed flights, 34%, arrived 15 minutes or more early. The 103 late arrivals split 24 under half an hour, 39 between 30 and 60 minutes, and 40 an hour or more.

15+ min early121 flights34.2%
Within 15 min130 flights36.7%
15–29 min late24 flights6.8%
30–59 min late39 flights11.0%
1–2 hours late23 flights6.5%
2+ hours late17 flights4.8%

Scale runs 0% to 100%.

Share of 354 completed flights by arrival against schedule.

18 of 87 late departures made up the time and arrived on time, 21% of them. In the other direction, 34 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 MIA.

The worst days

Worst days for Delta on DCA to MIA

The latest arrival of the period was on 14 July 2026, 6 hours 53 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. Three of the five worst days fell in July 2026.

The latest arrivals of Delta on DCA to MIA in the period
Date	Arrived late by	Largest filed cause
14 July 2026	6 hours 53 minutes	National Airspace System
30 December 2025	6 hours 28 minutes	Carrier
18 July 2026	4 hours	Carrier
3 August 2026	3 hours 39 minutes	Carrier
6 July 2026	3 hours 24 minutes	National Airspace System

Delay causes

Why Delta runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,697 reported delay minutes.

National Airspace System
42%
Carrier
31%
Late-arriving aircraft
26%
Extreme weather
2%

42% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 3,207 minutes out of 7,697, against a national NAS share of 21%. The split is drawn from 7,697 reported delay minutes.

Cancellations are rare at 0.83%, 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

11.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection 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.

The return leg is a different operation and performs like one: it runs 78.9% on time across 363 flights, 8 points above 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 DCA to MIA

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 70.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 354 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures