Carrier route record
UADEN→DCA
United Airlines · Denver to Washington
- Flights
- 364
- Period
- September 2025 to August 2026
- Share of route
- 27%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on DEN to DCA earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 11 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 364 flights, with a median arrival 11 minutes early.
Set against the rest of the country, United's DEN to DCA record is 11 points better than the US average of 77.3%. That gap is worth roughly 113 fewer late arrivals for every thousand flights.
Key figures
On time
88.6%
Arrivals under 15 minutes late, of 361 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
0.27%
National rate is 1.89%
Whole route
80.6%
Every carrier on DEN to DCA, 1,347 flights
These figures cover 364 flights between September 2025 and August 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.
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Carrier by carrier
United against every carrier on DEN to DCA
United flew 364 of the 1,347 flights on DEN to DCA, about 27% of it. Its 88.6% on time is 8 points better than the route as a whole, which runs 80.6%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 88.6% to Frontier at 77.5%.
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 |
|---|---|---|---|---|---|
| United Airlines (this page)thin sample | 364 | 88.6% | 59 min | 0.27% | A+ |
| Frontier Airlines | 983 | 77.5% | 72 min | 0.81% | B+ |
Flight by flight
United flight numbers on DEN to DCA
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Departure window
When United 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 364 flights.
There are not enough flights in each departure window to split United's DEN to DCA record by time of day without the percentages moving on noise. The headline rate of 88.6% is the reliable figure here.
Across the year
United on DEN to DCA through the year
May is the best month on the calendar at 96.8% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. January was the busiest month here, with 31 flights.
Across the week, Tuesday is the strongest day at 96.0% on time and Friday the weakest at 78.8%, a spread of 17 points.
Arrival by arrival
How late United on DEN to DCA runs when it is late
United on DEN to DCA often beats the schedule: 141 of 361 completed flights, 39%, arrived 15 minutes or more early. The 41 late arrivals split 14 under half an hour, 16 between 30 and 60 minutes, and 11 an hour or more.
- 15+ min early141 flights39.1%
- Within 15 min179 flights49.6%
- 15–29 min late14 flights3.9%
- 30–59 min late16 flights4.4%
- 1–2 hours late5 flights1.4%
- 2+ hours late6 flights1.7%
Scale runs 0% to 100%.
Share of 361 completed flights by arrival against schedule.
10 of 38 late departures made up the time and arrived on time, 26% of them. 13 flights left on time and still arrived late.
The worst days
Worst days for United on DEN to DCA
The latest arrival of the period was on 30 November 2025, 3 hours 34 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 30 November 2025 | 3 hours 34 minutes | Late-arriving aircraft |
| 1 February 2026 | 3 hours 19 minutes | Carrier |
| 11 September 2025 | 2 hours 52 minutes | Late-arriving aircraft |
| 7 November 2025 | 2 hours 31 minutes | Late-arriving aircraft |
| 7 September 2025 | 2 hours 18 minutes | Carrier |
Delay causes
Why United runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 2,421 reported delay minutes.
- 41%National Airspace System
- 32%Late-arriving aircraft
- 28%Carrier
41% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 981 minutes out of 2,421, against a national NAS share of 21%. The split is drawn from 2,421 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 88.6% on time here.
Cancellations are rare at 0.27%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 3.0% land an hour or more behind schedule, against 8.3% 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 1,476 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 78.4% on time across 364 flights, 10 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 10 points of difference.
One caution: this is a thin sample. 364 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 United on DEN to DCA
Put together: treat all of this as provisional. 364 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 88.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 361 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to DCA, every carrier
- United on DCA to DEN, the return leg
- Frontier Airlines on DEN to DCA77.5%
- United Airlines network-wide record
- Denver International (DEN) delay statistics
- Ronald Reagan Washington National (DCA) delay statistics
- Worst months to fly in the US, ranked by the data
- The best day of the week to fly, and why it is the second lever
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.