Carrier route record
F9MIA→RDU
Frontier Airlines · Miami to Raleigh
- Flights
- 185
- Period
- July 2025 to June 2026
- Share of route
- 8%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on MIA to RDU lands a B, about a point 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 a little over an hour on average. That is a workable record, not a spotless one. That rests on 185 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 Frontier on MIA to RDU from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.6%
Arrivals under 15 minutes late, of 182 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
1.62%
National rate is 1.81%
Whole route
71.4%
Every carrier on MIA to RDU, 2,347 flights
These figures cover 185 flights between July 2025 and June 2026. Beyond the headline rate, 8.8% 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
Frontier against every carrier on MIA to RDU
Frontier flew 185 of the 2,347 flights on MIA to RDU, about 8% of it. Its 78.6% on time is 7 points better than the route as a whole, which runs 71.4%. Ranked by on-time rate it is number two of five carriers on the route, where the range runs from Envoy at 88.7% to Republic at 64.3%. 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 |
|---|---|---|---|---|---|
| Envoy Airthin sample | 72 | 88.7% | 42 min | 1.39% | A |
| Frontier Airlines (this page)thin sample | 185 | 78.6% | 70 min | 1.62% | B |
| American Airlines | 1,700 | 71.4% | 72 min | 1.47% | C |
| Delta Air Linesthin sample | 360 | 64.7% | 95 min | 2.50% | D |
| Republic Airwaysthin sample | 30 | 64.3% | 80 min | 6.67% | D− |
Departure window
When Frontier runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 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–8am50 flights89.8%
- 8am–11am24 flights—
- 11am–2pm59 flights77.2%
- 2pm–5pm43 flights76.7%
- 5pm–8pm8 flights—
- 8pm–5am1 flights—
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 89.8% of the time, against 76.7% for the afternoon window. That is 13 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 59 flights scheduled in it.
Across the year
Frontier on MIA to RDU through the year
- Jul–Sep 202533 flights72.7%
- Oct–Dec 202544 flights67.4%
- Jan–Mar 202648 flights80.4%
- Apr–Jun 202660 flights88.3%
Scale runs 60% 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 78.6% on time across 185 flights.
Frontier on MIA to RDU did not run the same all year. Its best quarter was Apr–Jun 2026 at 88.3% on time and its weakest Oct–Dec 2025 at 67.4%, a swing of 21 points on roughly 46 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, Thursday is the strongest day at 91.2% on time and Sunday the weakest at 67.5%. 24 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Frontier runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 55% of the 2,732 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.
- 55%Late-arriving aircraft
- 22%Carrier
- 18%National Airspace System
- 4%Extreme weather
55% 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 2,732 reported delay minutes here, that single category outweighs weather by 12 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 2,732 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 89.8% on time here.
Cancellations sit at 1.62% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
8.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says 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 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 70.2% on time across 185 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. 185 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 Frontier on MIA to RDU
Put together: treat all of this as provisional. 185 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 78.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 182 completed flights over 12 months sit behind that.
Related
Where to go next
- MIA to RDU, every carrier
- Frontier on RDU to MIA, the return leg
- American Airlines on MIA to RDU71.4%
- Delta Air Lines on MIA to RDU64.7%
- Frontier Airlines network-wide record
- Miami International (MIA) delay statistics
- Raleigh-Durham International (RDU) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.