Carrier route record

DLRDU→MIA

Delta Air Lines · Raleigh to Miami

Flights: 360
Period: July 2025 to June 2026
Share of route: 15%
Carriers: 5

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.

Delta on RDU to MIA lands a B, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 360 flights, with a median arrival 9 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Delta on RDU to MIA from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

80.5%

Arrivals under 15 minutes late, of 354 completed flights

Avg delay

82 min

Across delayed arrivals only, not all flights

Cancelled

1.67%

National rate is 1.81%

Whole route

76.8%

Every carrier on RDU to MIA, 2,350 flights

These figures cover 360 flights between July 2025 and June 2026. Beyond the headline rate, 10.2% 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

Delta against every carrier on RDU to MIA

Delta flew 360 of the 2,350 flights on RDU to MIA, about 15% of it. Its 80.5% on time is 4 points better than the route as a whole, which runs 76.8%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from Delta at 80.5% to Republic at 58.6%. Three 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 RDU to MIA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines (this page)thin sample	360	80.5%	82 min	1.67%	B
American Airlines	1,705	77.2%	102 min	1.64%	B
Envoy Airthin sample	70	72.5%	55 min	1.43%	C
Frontier Airlinesthin sample	185	70.2%	89 min	3.78%	C−
Republic Airwaysthin sample	30	58.6%	49 min	3.33%	D−

Flight by flight

Delta flight numbers on RDU to MIA

DL 89008:0880.5% · 360 flights

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 360 flights.

There are not enough flights in each departure window to split Delta's RDU to MIA record by time of day without the percentages moving on noise. The headline rate of 80.5% is the reliable figure here.

Across the year

Delta on RDU to MIA through the year

Jul–Sep 202592 flights74.7%
Oct–Dec 202588 flights87.5%
Jan–Mar 202689 flights74.7%
Apr–Jun 202691 flights85.2%

Scale runs 65% to 95%. 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 80.5% on time across 360 flights.

Delta on RDU to MIA did not run the same all year. Its best quarter was Oct–Dec 2025 at 87.5% on time and its weakest Jan–Mar 2026 at 74.7%, a swing of 13 points on roughly 90 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Across the week, Sunday is the strongest day at 84.0% on time and Friday the weakest at 76.5%. 8 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 76% of the 5,672 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.

Carrier
76%
National Airspace System
20%
Extreme weather
3%
Late-arriving aircraft
1%

The largest share of delay minutes, 76%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 4,322 of the 5,672 delay minutes reported here. The split is drawn from 5,672 reported delay minutes.

Cancellations sit at 1.67% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.2% 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 700 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 is a different operation and performs like one: it runs 64.7% on time across 360 flights, 16 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 16 points of difference.

One caution: this is a thin sample. 360 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 RDU to MIA

Put together: treat all of this as provisional. 360 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 80.5% 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures