Route profile
RDU→DEN
Flight reliability, delays and best times to fly from Raleigh–Durham to Denver, 1,436 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 64% of comparable major US routes (4,598 compared)
Calculated from 5,882 flights. How this is calculated · What counts as on time
RDU → DEN arrives on time 80.8% of the time; the return trip, DEN → RDU, arrives on time 73.4% of the time, a 7.5-point gap between the two directions of the same city pair.
RDU → DEN spends 24.9 minutes on the ground on a 1,436-mile trip: 14.5 minutes from pushback to wheels-up at RDU and 10.4 minutes from touchdown to gate at DEN.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where RDU to DEN differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
RDU to DEN struggles most at 6 PM: 59.8% of its flights scheduled then arrive on time, 10.6 points behind the 70.4% on routes of similar length at the same hour. Against all other routes the gap is 8.8 points.
RDU to DEN is at its best against routes of similar length for flights scheduled at 10 AM: 88.9% arrive on time, 8.1 points ahead of the 80.8% those routes manage at that hour. Against all other routes the gap is 6.2 points.
RDU to DEN holds up on Sundays better than routes of similar length do: 83.0% on time to their 75.4%, a 7.6 points lead. Against all other routes the gap is 8.2 points.
March is kinder to RDU to DEN than to routes of similar length: 86.9% on time against 78.0%, 8.9 points better. Against all other routes the gap is 9 points.
Frontier Airlines does better on RDU to DEN than on its routes of similar length: 76.7% on time here, 69.7% there, 7 points apart. Against all other routes the gap is 5.5 points.
RDU to DEN against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 6 PM departures | 59.8% | routes of similar length | 70.4% | −10.6 pts | 368 here, 108,809 there |
| Hour: 10 AM departures | 88.9% | routes of similar length | 80.8% | +8.1 pts | 359 here, 83,305 there |
| Weekday: Sunday | 83.0% | routes of similar length | 75.4% | +7.6 pts | 843 here, 227,752 there |
| Month: March | 86.9% | routes of similar length | 78.0% | +8.9 pts | 459 here, 131,959 there |
| Airline: Frontier Airlines | 76.7% | routes of similar length | 69.7% | +7.0 pts | 1,103 here, 64,415 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,436 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
Why RDU → DEN flights are cancelled
July 2023 – July 2026
RDU → DEN cancelled 51 of 5,882 scheduled flights — about 1 in every 115. The reason filed most often was the airline, 51.0% of the cancellations coded on this route — about 1 in every 226 scheduled flights.
Share of cancellations
Of 51 cancelled departures carrying a reason code.
What each reason means
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
26 cancellations, 51.0% of the total.
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
23 cancellations, 45.1% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
2 cancellations, 3.9% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
51 coded cancellations were recorded on RDU → DEN; the section appears from 50.
When it goes wrong
July 2023 – July 2026
38 min late
against a median of 7 min early
Percentiles over 5,882 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at DEN after arriving from RDU.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 35% | Likely to miss |
| 45 min | 19% | High risk |
| 60 min | 12% | Some risk |
| 90 min | 6.5% | Some risk |
| 120 min | 4.0% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.87% of the time and diverts 0.31% of the time, which a late arrival never shows up in.
Chance of missing is the share of 5,813 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 38 minutes late (90th-percentile gate arrival delay), over 5,882 operations.
Any other layover length: connection checker.
Best time to fly
RDU → DEN flights departing 12–3 PM arrived on time 89.8% of the time, against 63.0% for 6–9 PM departures, a gap of 26.8 percentage points.
By departure window
By departure hour
- 12 AM to 4 AM: too few flights to score
- 5 AM: 91.7% on time from 715 flights
- 6 AM: 93.7% on time from 271 flights
- 7 AM: 93.8% on time from 324 flights
- 8 AM: 86.6% on time from 1,196 flights
- 9 AM: too few flights to score
- 10 AM: 88.9% on time from 364 flights
- 11 AM to 3 PM: too few flights to score
- 4 PM: 76.4% on time from 1,250 flights
- 5 PM: 66.8% on time from 621 flights
- 6 PM: 59.8% on time from 372 flights
- 7 PM: 62.3% on time from 185 flights
- 8 PM to 11 PM: too few flights to score
Why RDU → DEN runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for RDU → DEN. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on RDU → DEN, at 41.8%: flights here mostly leave late because the plane came in late, and the day shows it: 12–3 PM departures arrived on time 89.8% of the time and 6–9 PM departures 63.0%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| United Airlines | 2,597 | 85.3% | 0.73% | -9 min | 5.3% |
| Southwest Airlines | 2,160 | 77.6% | 0.60% | -4 min | 6.4% |
| Frontier Airlines | 1,125 | 76.7% | 1.69% | -9 min | 10.1% |
United Airlines flew 44.2% of the 5,882 flights listed. Frontier Airlines cancelled 1.69% of its flights here against 0.60% for Southwest Airlines.
United Airlines arrived on time 8.6 percentage points more often than Frontier Airlines on this route.
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Friday the least, a gap of 6.3 percentage points.
By month
- Jan: 82.1%
- Feb: 84.5%
- Mar: 86.9%
- Apr: 80.0%
- May: 75.4%
- Jun: 76.0%
- Jul: 73.5%
- Aug: 74.5%
- Sep: 82.8%
- Oct: 89.2%
- Nov: 86.5%
- Dec: 83.8%
July is historically the weakest month and October the strongest, a spread of 15.7 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 73.6% from 207 flights
- August 2023: 76.0% from 211 flights
- September 2023: 82.2% from 208 flights
- October 2023: 90.9% from 209 flights
- November 2023: 91.8% from 183 flights
- December 2023: 91.0% from 156 flights
- January 2024: 83.1% from 148 flights
- February 2024: 80.7% from 135 flights
- March 2024: 86.5% from 166 flights
- April 2024: 77.0% from 148 flights
- May 2024: 66.2% from 160 flights
- June 2024: 86.7% from 179 flights
- July 2024: 75.1% from 185 flights
- August 2024: 76.0% from 169 flights
- September 2024: 85.5% from 153 flights
- October 2024: 90.8% from 155 flights
- November 2024: 81.6% from 152 flights
- December 2024: 89.9% from 148 flights
- January 2025: 76.6% from 141 flights
- February 2025: 85.0% from 127 flights
- March 2025: 89.2% from 148 flights
- April 2025: 80.1% from 142 flights
- May 2025: 70.8% from 146 flights
- June 2025: 65.1% from 178 flights
- July 2025: 66.5% from 183 flights
- August 2025: 71.1% from 163 flights
- September 2025: 80.5% from 133 flights
- October 2025: 84.6% from 136 flights
- November 2025: 84.8% from 138 flights
- December 2025: 69.9% from 147 flights
- January 2026: 86.9% from 138 flights
- February 2026: 88.1% from 128 flights
- March 2026: 85.1% from 149 flights
- April 2026: 83.0% from 147 flights
- May 2026: 89.0% from 155 flights
- June 2026: 76.5% from 154 flights
- July 2026: 79.5% from 157 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 81.4% against 79.3% in the 12 months before — improving by 2.1 percentage points.
Data and methodology
Calculated by FlyerIntel from 5,882 RDU → DEN flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed