PlainFlights

Route · IAD → DEN · 2020–2025 BTS data

Washington to Denver

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), IAD to DEN (Washington to Denver) ranks #458 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

83.1%
On-time
+4.1 pts
vs US avg
72 min
Delay when late
17,372
Flights
#458 of 4927
Corpus placement

Cancelled

0.9%

Best Month

Nov 2025 91%

Worst Month

Jul 2025 69%

Distance

1,452 mi

Carriers

2

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 304 69 1 2 WN,UA
Nov 2025 276 24 1 0 UA,WN
Oct 2025 283 46 0 0 UA,WN
Sep 2025 294 44 0 1 UA,WN
Aug 2025 335 78 1 6 WN,UA
Jul 2025 361 111 5 8 UA,WN
Jun 2025 327 86 3 3 UA,WN
May 2025 311 78 1 0 UA,WN
Apr 2025 292 63 1 2 UA,WN
Mar 2025 293 30 1 1 UA,WN
Feb 2025 230 48 0 2 UA,WN
Jan 2025 254 50 1 1 UA,WN
Dec 2024 273 32 3 0 UA,WN
Nov 2024 279 25 2 0 UA,WN
Oct 2024 283 26 2 0 UA,WN
Sep 2024 287 31 3 0 WN,UA
Aug 2024 296 70 2 0 WN,UA
Jul 2024 303 63 1 3 UA,WN
Jun 2024 290 69 4 1 UA,WN
May 2024 301 84 3 1 UA,WN
Apr 2024 262 56 3 0 UA,WN
Mar 2024 253 27 1 0 UA,WN
Feb 2024 201 34 0 0 UA,WN
Jan 2024 221 47 25 0 WN,UA

IAD–DEN seasonal on-time pattern

Best: November (90.4%) · weakest: July (75.0%)

70%75%80%85%90%95% JanFebMarAprMayJunJulAugSepOctNovDec 82.1%

Strongest calendar month

November

90.4% on-time · ~237 flights/mo

Busiest calendar month

August

~273 flights/mo avg

Weakest calendar month

July

75.0% on-time · ~264 flights/mo

Cancellation Rate

0.9%

64 of 6,809 flights

Diversion Rate

0.5%

31 of 6,809 flights

Explore origin & destination

On-time and delay data for the airports this route connects.

IAD - Washington

Full on-time, delay-cause, and seasonal performance for Washington, DC.

IAD on-time profile

DEN - Denver

Full on-time, delay-cause, and seasonal performance for Denver, CO.

DEN on-time profile

Compare the two airports

See IAD and DEN side by side on delays, cancellations, and reliability.

Compare IAD vs DEN

Origin-hub reliability standing

Mid-pack among IAD departures

From IAD, this corridor sits with 42 other 75–85% on-time routes out of 58 tracked departures, not the hub's reliability leaders (14 at ≥85%) and not the softest ( 2 below 75%). Destination: Denver · fleet on-time rank #1912 of 4927.

What the Data Says About IAD to DEN

Bureau of Transportation Statistics records show Washington to Denver (IAD to DEN) running a 83.1% on-time rate over 17,372 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 71.5 minutes. The 1,452-mile corridor is served by 2 carriers, and over the last 24 months 0.9% of 6,809 flights were cancelled, 0.5% diverted.

The monthly split is wide on this route: Nov 2025 posted the strongest performance at 91% on-time, while Jul 2025 came in at just 69% - a 22-point swing worth factoring into travel timing.

On the multi-year calendar, IAD–DEN peaks in November at 90.4% on-time while August carries the heaviest traffic (~273 flights per month) ; the softest month is July at 75.0%, a 15.4-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does IAD to DEN rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, IAD to DEN ranks #458 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from IAD to DEN? ▼
Flights from Washington to Denver have a 83.1% on-time rate based on 17,372 flights. The average delay is 71.5 minutes. The best recent month was Nov 2025 with 91% on-time.
What is the cancellation rate for IAD to DEN? ▼
Over the last 24 months, 0.9% of flights on this route were cancelled (64 of 6,809 flights) and 0.5% were diverted.
How far is the flight from IAD to DEN? ▼
The flight distance from Washington (IAD) to Denver (DEN) is approximately 1,452 miles. This route is served by 2 carriers.
When is the best time to fly from IAD to DEN? ▼
The best recent month for on-time performance was Nov 2025 (91% on-time). The worst was Jul 2025 (69% on-time). Consider booking during months with historically better performance.

Airports on this route

IAD Airport

Washington
DEN Airport

Denver
Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Read our methodology - how this data is sourced, computed, and verified.

Using IAD–DEN data

IAD–DEN runs 4.1 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare IAD and DEN airport profiles: delay causes and top routes differ even on the same corridor. IAD airport
  • If your dates flex, November (90.4% on-time) beats July (75.0%) on this corridor. Seasonal chart
  • 4 other routes post a similar 83.1% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.