Routes › Denver (DEN) › DEN to IAD
Route · 12 months to July 2026
Denver to Washington: on-time record
Denver International to Washington Dulles International
BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report. Data through July 2026; this is a monthly history, not live flight status.
80.8% of scheduled DEN to IAD flights arrived on time in the 12 months to July 2026. The figure covers 3,463 flights between Denver and Washington by carriers that report to BTS, a distance of 1,452 miles.
That is 4.8 points above the national on-time share of 76.0% for the same period and 4.7 points above the 76.1% recorded for all departures from DEN. Flights that did arrive were 3.1 min late on average, and 0.5% of scheduled flights were cancelled (national: 1.8%).
2 reporting carriers flew the route at least 60 times. United Airlines had the highest on-time share at 84.5% of 2,786 flights; Southwest Airlines had the lowest at 65.7% of 677.
By scheduled departure hour (local time at DEN), flights leaving from 6 am to 7 am had the highest on-time share, 93.8%; those leaving from 7 pm to 8 pm had the lowest, 50.4%.
The on-time share is up 3.0 points on the previous 12 months (77.8%); cancellations moved from 0.6% to 0.5%.
Of the delay minutes that carriers assigned to a BTS cause category on this route, late-arriving aircraft 47%, air carrier 31% and national aviation system 21%.
- On time 80.8%
- Arrived 15+ minutes late 18.7%
- Cancelled 0.5%
- Diverted 0.0%
Airlines on the route compared
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| UA United Airlines | 2,786 | 80% | 84.5% | 0.2 min | 0.4% |
| WN Southwest Airlines | 677 | 20% | 65.7% | 14.7 min | 0.9% |
Carriers with at least 24 flights in the 12 months to July 2026. The on-time pill is green when a carrier is at or above the route's overall share. Regional carriers operate flights sold under larger airlines' brands; BTS lists the carrier that operated the flight.
Compared with the airports and the nation
| Measure | DEN to IAD | All departures from DEN | All arrivals at IAD | All reported flights |
|---|---|---|---|---|
| Arrived on time | 80.8% | 76.1% | 81.9% | 76.0% |
| Arrived 15+ minutes late | 18.7% | 22.9% | 16.5% | 21.9% |
| Cancelled | 0.5% | 0.7% | 1.4% | 1.8% |
| Diverted | 0.0% | 0.3% | 0.1% | 0.3% |
| Average arrival delay | 3.1 min | 7.8 min | 3.5 min | 8.1 min |
| Delay minutes per 100 flights | 1,219 | 1,568 | 1,334 | 1,684 |
| Scheduled flights | 3,463 | 319,208 | 57,761 | 7,043,858 |
12 months to July 2026. Delay minutes count late arrivals only (an early arrival is zero), so the per-100-flights row is a normalised total rather than an average of early and late.
The return direction, IAD to DEN, recorded 82.1% on time across 3,465 flights in the same period.
Month by month
Year on year: on time 80.8% against 77.8% (+3.0 pts), cancelled 0.5% against 0.6%, flights 3,463 against 3,484.
By scheduled departure hour
Delay causes
Seasonality
| Calendar month | Flights | On time | Cancelled | Avg arrival delay | Years in sample |
|---|---|---|---|---|---|
| Jan | 754 | 74.3% | 7.0% | 5.2 min | 3 |
| Feb | 688 | 82.3% | 0.0% | 5.8 min | 3 |
| Mar | 846 | 78.4% | 0.4% | 6.7 min | 3 |
| Apr | 845 | 81.8% | 0.1% | 1.4 min | 3 |
| May | 928 | 73.9% | 0.4% | 11.2 min | 3 |
| Jun | 878 | 72.3% | 1.0% | 11.3 min | 3 |
| Jul | 929 | 67.9% | 1.0% | 18.3 min | 3 |
| Aug | 908 | 74.8% | 0.4% | 9.7 min | 3 |
| Sep | 826 | 79.8% | 0.6% | 5.4 min | 3 |
| Oct | 815 | 85.5% | 0.0% | -2.0 min | 3 |
| Nov | 757 | 84.9% | 0.5% | -1.2 min | 3 |
| Dec | 815 | 84.2% | 0.5% | 1.1 min | 3 |
Each calendar month summed across the 36 months on file, so most rows combine three years. The pill compares the month with the route's own 12-month share.
Other routes from Denver (DEN)
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| DEN–PHX | Denver to Phoenix | 8,973 | 75.3% | 9.5 min | 0.8% |
| DEN–SLC | Denver to Salt Lake City | 7,733 | 78.4% | 5.6 min | 0.4% |
| DEN–LAX | Denver to Los Angeles | 7,708 | 78.7% | 5.1 min | 0.5% |
| DEN–LAS | Denver to Las Vegas | 7,133 | 75.1% | 8.3 min | 0.6% |
| DEN–SEA | Denver to Seattle | 6,317 | 74.2% | 8.1 min | 0.6% |
| DEN–ORD | Denver to Chicago | 6,131 | 71.0% | 17.7 min | 1.1% |
| DEN–DFW | Denver to Dallas/Fort Worth | 6,036 | 73.7% | 13.0 min | 2.0% |
| DEN–SAN | Denver to San Diego | 6,035 | 74.7% | 6.3 min | 0.7% |
All 193 routes and the airport record for DEN · airport record for IAD
Questions and answers
How often are flights from Denver to Washington on time?
80.8% of the 3,463 flights scheduled from DEN to IAD in the 12 months to July 2026 arrived less than 15 minutes after their scheduled time. The national share for the same period was 76.0%. Cancelled and diverted flights count as not on time.
Which airline has the highest on-time share from DEN to IAD?
Among reporting carriers with at least 60 flights on the route, United Airlines had the highest on-time share (84.5%), followed by Southwest Airlines (65.7%). Differences of a point or two on a few hundred flights are small.
What causes delays between Denver and Washington?
For flights that arrived 15 or more minutes late, carriers attributed the delay minutes as follows: late-arriving aircraft 47%, air carrier 31%, national aviation system 21%, extreme weather 1%, security 1%. The categories are the carriers' own reports to BTS; weather that slows the wider system is usually recorded under the National Aviation System rather than extreme weather.
What time of day has the highest on-time share from DEN?
Flights scheduled to leave DEN from 6 am to 7 am arrived on time 93.8% of the time, the highest of any hour with enough flights to compare. The lowest was 7 pm to 8 pm at 50.4%. Delays tend to build through the day as late aircraft carry over to later flights.
Is it getting better?
The on-time share for the 12 months to July 2026 was 80.8%, up 3.0 points on the previous 12 months (77.8%). The monthly chart on this page shows each of the last 36 months. Across those months, October had the highest on-time share (85.5%) and July the lowest (67.9%).
Where does this data come from?
Every figure is computed from the Bureau of Transportation Statistics Reporting Carrier On-Time Performance files, which list each scheduled domestic flight by the carriers required to report. This page covers August 2023 to July 2026. It shows totals and averages only; it is not a live flight-status service.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987 to present), monthly files August 2023 to July 2026, a US government work in the public domain. Figures are totals and averages over all scheduled flights by reporting carriers on the route; no individual flight or aircraft is identified. Times are local to the departure airport. The load factor and passenger counts from the BTS T-100 series are not included in this edition. See the methodology; report processing errors through corrections.