Carrier route record
F9RDU→DEN
Frontier Airlines · Raleigh to Denver
- Flights
- 297
- Period
- September 2025 to August 2026
- Share of route
- 17%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on RDU to DEN 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 a little over an hour. That rests on 297 flights. The strongest carrier on the route with a full sample, United Airlines, flew 727 at 87.7% on time.
Set against the rest of the country, Frontier's RDU to DEN record is 7 points better than the US average of 77.3%. That gap is worth roughly 73 fewer late arrivals for every thousand flights.
Key figures
On time
84.6%
Arrivals under 15 minutes late, of 293 completed flights
Avg delay
79 min
Across delayed arrivals only, not all flights
Cancelled
1.01%
National rate is 1.89%
Whole route
81.9%
Every carrier on RDU to DEN, 1,734 flights
These figures cover 297 flights between September 2025 and August 2026. The median arrival is 15 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
Frontier against every carrier on RDU to DEN
Frontier flew 297 of the 1,734 flights on RDU to DEN, about 17% of it. Its 84.6% on time is 3 points better than the route as a whole, which runs 81.9%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from United at 87.7% to Southwest at 74.8%.
The choice of carrier is not cosmetic here. United Airlines arrives on time 87.7% of the time; Southwest Airlines manages 74.8%. Sample sizes sit next to every figure, because a two-point gap across 710 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 727 | 87.7% | 89 min | 0.41% | A+ |
| Frontier Airlines (this page)thin sample | 297 | 84.6% | 79 min | 1.01% | B |
| Southwest Airlines | 710 | 74.8% | 55 min | 0.99% | C+ |
The spread between United and Southwest is 13 points, wide enough that it should decide the booking. On a hundred trips that is 13 more arrivals inside the on-time window.
Flight by flight
Frontier flight numbers on RDU to DEN
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 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 20 points, against 13 points between the best and worst carrier.
- 5am–8am—
- 8am–11am1 flights—
- 11am–2pm105 flights96.1%
- 2pm–5pm3 flights—
- 5pm–8pm154 flights76.5%
- 8pm–5am34 flights84.8%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 96.1% on time, ahead of 5pm–8pm at 76.5%. 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 5pm–8pm window is the busiest, with 154 flights scheduled in it.
Across the year
Frontier on RDU to DEN through the year
- Jul–Sep 202517 flights—
- Oct–Dec 202565 flights73.8%
- Jan–Mar 202664 flights88.7%
- Apr–Jun 202689 flights90.8%
- Jul–Sep 202662 flights93.5%
Scale runs 65% to 100%. 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 84.6% on time across 297 flights.
Frontier on RDU to DEN did not run the same all year. Its best quarter was Jul–Sep 2026 at 93.5% on time and its weakest Oct–Dec 2025 at 73.8%, a swing of 20 points on roughly 74 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, Saturday is the strongest day at 91.9% on time and Monday the weakest at 75.5%, a spread of 16 points.
Arrival by arrival
How late Frontier on RDU to DEN runs when it is late
Frontier on RDU to DEN often beats the schedule: 148 of 293 completed flights, 51%, arrived 15 minutes or more early. The 45 late arrivals split 12 under half an hour, 16 between 30 and 60 minutes, and 17 an hour or more.
- 15+ min early148 flights50.5%
- Within 15 min100 flights34.1%
- 15–29 min late12 flights4.1%
- 30–59 min late16 flights5.5%
- 1–2 hours late13 flights4.4%
- 2+ hours late4 flights1.4%
Scale runs 0% to 100%.
Share of 293 completed flights by arrival against schedule.
A late pushback is often recovered here: of 55 departures that left 15 minutes late or more, 18 still arrived on time. 8 flights left on time and still arrived late.
The worst days
Worst days for Frontier on RDU to DEN
The latest arrival of the period was on 8 December 2025, 15 hours 13 minutes behind schedule; most of its delay minutes were filed as extreme weather. On four of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 8 December 2025 | 15 hours 13 minutes | Extreme weather |
| 13 March 2026 | 3 hours 33 minutes | Late-arriving aircraft |
| 6 March 2026 | 2 hours 18 minutes | Late-arriving aircraft |
| 15 August 2026 | 2 hours 11 minutes | Late-arriving aircraft |
| 24 November 2025 | 1 hour 46 minutes | Late-arriving aircraft |
Delay causes
Why Frontier runs late on this route
Late-arriving aircraft accounts for 48% of the 3,542 delay minutes carriers reported here, and the remaining four split what is left.
- 48%Late-arriving aircraft
- 26%Extreme weather
- 13%National Airspace System
- 13%Carrier
Extreme weather accounts for 26% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 4.3 times the usual weather exposure. The split is drawn from 3,542 reported delay minutes.
48% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 3,542 reported delay minutes here, that single category outweighs weather by 2 to one.
Cancellations sit at 1.01% against a national 1.89%, which is ordinary. Diversions add another 0.34%.
Connections and stage length
What a delay here costs
5.8% 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 a little over an hour, which a normal layover absorbs.
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.
The return leg runs 87.4% on time across 296 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 297 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 RDU to DEN
Put together: treat all of this as provisional. 297 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 84.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 293 completed flights over 12 months sit behind that.
Related
Where to go next
- RDU to DEN, every carrier
- Frontier on DEN to RDU, the return leg
- United Airlines on RDU to DEN87.7%
- Southwest Airlines on RDU to DEN74.8%
- Frontier Airlines network-wide record
- Raleigh-Durham International (RDU) delay statistics
- Denver International (DEN) delay statistics
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
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.