Carrier route record
DLRDU→MIA
Delta Air Lines · Raleigh to Miami
- Flights
- 360
- Period
- September 2025 to August 2026
- Share of route
- 15%
- Carriers
- 5
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on RDU to MIA earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs an hour and a half. That rests on 360 flights, with a median arrival 12 minutes early.
Set against the rest of the country, Delta's RDU to MIA record is 7 points better than the US average of 77.3%. That gap is worth roughly 69 fewer late arrivals for every thousand flights.
Key figures
On time
84.2%
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 1.89%
Whole route
77.8%
Every carrier on RDU to MIA, 2,367 flights
These figures cover 360 flights between September 2025 and August 2026. The median arrival is 12 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Carrier by carrier
Delta against every carrier on RDU to MIA
Delta flew 360 of the 2,367 flights on RDU to MIA, about 15% of it. Its 84.2% on time is 6 points better than the route as a whole, which runs 77.8%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from Delta at 84.2% 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines (this page)thin sample | 360 | 84.2% | 82 min | 1.67% | B |
| American Airlines | 1,666 | 78.4% | 104 min | 1.56% | B |
| Envoy Airthin sample | 102 | 74.3% | 69 min | 0.98% | C+ |
| Frontier Airlinesthin sample | 209 | 66.8% | 78 min | 3.35% | C− |
| Republic Airwaysthin sample | 30 | 58.6% | 49 min | 3.33% | D− |
Flight by flight
Delta flight numbers on RDU to MIA
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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 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 84.2% is the reliable figure here.
Across the year
Delta on RDU to MIA through the year
- Jul–Sep 202530 flights93.3%
- Oct–Dec 202588 flights87.5%
- Jan–Mar 202689 flights74.7%
- Apr–Jun 202691 flights85.2%
- Jul–Sep 202662 flights86.9%
Scale runs 65% to 100%.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 84.2% on time across 360 flights.
Delta on RDU to MIA did not run the same all year. Its best quarter was Jul–Sep 2025 at 93.3% on time and its weakest Jan–Mar 2026 at 74.7%, a swing of 19 points on roughly 72 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, Wednesday is the strongest day at 93.8% on time and Tuesday the weakest at 78.8%, a spread of 15 points.
Arrival by arrival
How late Delta on RDU to MIA runs when it is late
Delta on RDU to MIA often beats the schedule: 148 of 354 completed flights, 42%, arrived 15 minutes or more early. The 56 late arrivals split 11 under half an hour, 18 between 30 and 60 minutes, and 27 an hour or more.
- 15+ min early148 flights41.8%
- Within 15 min150 flights42.4%
- 15–29 min late11 flights3.1%
- 30–59 min late18 flights5.1%
- 1–2 hours late18 flights5.1%
- 2+ hours late9 flights2.5%
Scale runs 0% to 100%.
Share of 354 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 49 departures that left 15 minutes late or more, only 4 made it up before arrival. 11 flights left on time and still arrived late.
The worst days
Worst days for Delta on RDU to MIA
The latest arrival of the period was on 4 July 2026, 7 hours 12 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 4 July 2026 | 7 hours 12 minutes | Carrier |
| 20 January 2026 | 4 hours 36 minutes | Carrier |
| 29 January 2026 | 4 hours 19 minutes | Carrier |
| 12 June 2026 | 3 hours 50 minutes | Carrier |
| 4 April 2026 | 3 hours 40 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Carrier accounts for 79% of the 4,613 delay minutes carriers reported here, and the remaining four split what is left.
- 79%Carrier
- 19%National Airspace System
- 2%Extreme weather
The largest share of delay minutes, 79%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,626 of the 4,613 delay minutes reported here. The split is drawn from 4,613 reported delay minutes.
Cancellations sit at 1.67% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
7.6% 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 an hour and a half, which a normal layover absorbs.
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.
The return leg is a different operation and performs like one: it runs 67.3% on time across 360 flights, 17 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 17 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 84.2% 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.
Related
Where to go next
- RDU to MIA, every carrier
- Delta on MIA to RDU, the return leg
- American Airlines on RDU to MIA78.4%
- Envoy Air on RDU to MIA74.3%
- Frontier Airlines on RDU to MIA66.8%
- Delta Air Lines network-wide record
- Raleigh-Durham International (RDU) delay statistics
- Miami International (MIA) delay statistics
- The best day of the week to fly, and why it is the second lever
- How to read this site: grades, sample sizes, and honest caveats
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.