Carrier route record

F9DEN→RDU

Frontier Airlines · Denver to Raleigh

Flights: 285
Period: July 2025 to June 2026
Share of route: 16%
Carriers: 3

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

Frontier on DEN to RDU earns an A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 285 flights. The strongest carrier on the route with a full sample, United Airlines, flew 775 at 80.9% on time.

Set against the rest of the country, Frontier's DEN to RDU record is 9 points better than the US average of 77.6%. That gap is worth roughly 85 fewer late arrivals for every thousand flights.

On time

86.1%

Arrivals under 15 minutes late, of 281 completed flights

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

1.40%

National rate is 1.81%

Whole route

75.2%

Every carrier on DEN to RDU, 1,768 flights

These figures cover 285 flights between July 2025 and June 2026. The median arrival is 11 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.

Carrier by carrier

Frontier against every carrier on DEN to RDU

Frontier flew 285 of the 1,768 flights on DEN to RDU, about 16% of it. Its 86.1% on time is 11 points better than the route as a whole, which runs 75.2%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Frontier at 86.1% to Southwest at 64.6%.

The choice of carrier is not cosmetic here. United Airlines arrives on time 80.9% of the time; Southwest Airlines manages 64.6%. Sample sizes sit next to every figure, because a two-point gap across 708 flights means less than a ten-point one.

On-time performance by carrier on DEN to RDU
Airline	Flights	On time	Avg delay	Cancelled	Grade
Frontier Airlines (this page)thin sample	285	86.1%	54 min	1.40%	A
United Airlines	775	80.9%	60 min	0.52%	B+
Southwest Airlines	708	64.6%	53 min	0.71%	D+

The spread between United and Southwest is 16 points, wide enough that it should decide the booking. On a hundred trips that is 16 more arrivals inside the on-time window.

Flight by flight

Frontier flight numbers on DEN to RDU

F9 244011:0586.1% · 285 flights

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 11 points, against 16 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am57 flights94.6%
8am–11am7 flights—
11am–2pm201 flights83.9%
2pm–5pm20 flights—
5pm–8pm—
8pm–5am—

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

The weak window here is the middle of the day, not the evening: 11am–2pm runs 83.9% on time against 94.6% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 11am–2pm window is the busiest, with 201 flights scheduled in it.

Across the year

Frontier on DEN to RDU through the year

Jul–Sep 202568 flights85.1%
Oct–Dec 202565 flights81.5%
Jan–Mar 202664 flights88.7%
Apr–Jun 202688 flights88.5%

Scale runs 75% 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 86.1% on time across 285 flights.

Quarter by quarter Frontier on DEN to RDU held fairly steady: 85.1% in Jul–Sep 2025, 81.5% in Oct–Dec 2025, 88.7% in Jan–Mar 2026 and 88.5% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Saturday is the strongest day at 97.3% on time and Sunday the weakest at 79.6%. 18 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. Carrier accounts for 48% of the 2,085 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
48%
Late-arriving aircraft
36%
National Airspace System
15%
Extreme weather
1%

36% 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 2,085 reported delay minutes here, that single category outweighs weather by 36 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 2,085 reported delay minutes.

The largest share of delay minutes, 48%, 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 996 of the 2,085 delay minutes reported here.

Cancellations sit at 1.40% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 4.3% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The 1,436 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 77.5% on time across 286 flights, 9 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 9 points of difference.

One caution: this is a thin sample. 285 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 DEN to RDU

Put together: treat all of this as provisional. 285 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 86.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 281 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