PlainFlights

Route · IAD → PHL · 2020–2025 BTS data

Washington to Philadelphia

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), IAD to PHL (Washington to Philadelphia) ranks #4698 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

81.6%
On-time
+2.6 pts
vs US avg
83 min
Delay when late
760
Flights
#4698 of 4927
Corpus placement

Cancelled

3.9%

Best Month

Aug 2020 92%

Worst Month

Aug 2021 67%

Distance

135 mi

Carriers

6

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Nov 2025 50 6 5 0 YX
Feb 2022 74 12 3 0 YV,YX,UA
Jan 2022 63 13 12 0 UA,YV,YX
Dec 2021 31 9 0 0 UA,YV
Oct 2021 86 18 2 0 UA,YV,YX
Sep 2021 88 15 0 0 YV,YX
Aug 2021 93 31 0 0 YV,YX
Jul 2021 61 18 5 0 YV,YX
Jan 2021 47 2 2 0 YX
Oct 2020 53 5 0 0 YV
Aug 2020 62 5 1 0 YV
Jul 2020 52 6 0 0 YV

IAD–PHL seasonal on-time pattern

Best: November (88.0%) · weakest: December (71.0%)

70%75%80%85%90% JanFebJulAugSepOctNovDec 71%

Strongest calendar month

November

88.0% on-time · ~50 flights/mo

Busiest calendar month

September

~88 flights/mo avg

Weakest calendar month

December

71.0% on-time · ~31 flights/mo

Cancellation Rate

3.9%

30 of 760 flights

Diversion Rate

0.0%

0 of 760 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

PHL - Philadelphia

Full on-time, delay-cause, and seasonal performance for Philadelphia, PA.

PHL on-time profile

Compare the two airports

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

Compare IAD vs PHL

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: Philadelphia · fleet on-time rank #2512 of 4927.

What the Data Says About IAD to PHL

760 tracked flights put the IAD to PHL pairing (Washington to Philadelphia) at a 81.6% on-time rate, squarely in line with the wider network. Delays that do occur run 83.3 minutes on average. Across the 135-mile route and its 6 carriers, the trailing 24 months show 3.9% cancelled and 0.0% diverted (760 flights sampled).

The monthly split is wide on this route: Aug 2020 posted the strongest performance at 92% on-time, while Aug 2021 came in at just 67% - a 25-point swing worth factoring into travel timing.

On the multi-year calendar, IAD–PHL peaks in November at 88.0% on-time while September carries the heaviest traffic (~88 flights per month) ; the softest month is December at 71.0%, a 17.0-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does IAD to PHL rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, IAD to PHL ranks #4698 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 PHL? ▼
Flights from Washington to Philadelphia have a 81.6% on-time rate based on 760 flights. The average delay is 83.3 minutes. The best recent month was Aug 2020 with 92% on-time.
What is the cancellation rate for IAD to PHL? ▼
Over the last 24 months, 3.9% of flights on this route were cancelled (30 of 760 flights) and 0.0% were diverted.
How far is the flight from IAD to PHL? ▼
The flight distance from Washington (IAD) to Philadelphia (PHL) is approximately 135 miles. This route is served by 6 carriers.
When is the best time to fly from IAD to PHL? ▼
The best recent month for on-time performance was Aug 2020 (92% on-time). The worst was Aug 2021 (67% on-time). Consider booking during months with historically better performance.

Airports on this route

IAD Airport

Washington
PHL Airport

Philadelphia
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–PHL data

IAD–PHL is mid-pack at 81.6% on-time; month and carrier mix move more than the corridor headline.

  • Compare IAD and PHL airport profiles: delay causes and top routes differ even on the same corridor. IAD airport
  • If your dates flex, November (88.0% on-time) beats December (71.0%) on this corridor. Seasonal chart
  • 4 other routes post a similar 81.6% 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.