PlainFlights

Route · IAD → BOS · 2020–2025 BTS data

Washington to Boston

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), IAD to BOS (Washington to Boston) ranks #1650 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

80.6%
On-time
+1.6 pts
vs US avg
75 min
Delay when late
7,619
Flights
#1650 of 4927
Corpus placement

Cancelled

1.1%

Best Month

Feb 2024 92%

Worst Month

Sep 2025 58%

Distance

413 mi

Carriers

9

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 122 29 0 0 YX,UA
Nov 2025 119 26 2 0 UA
Oct 2025 124 32 1 0 UA
Sep 2025 142 59 2 0 UA
Aug 2025 134 27 0 0 UA
Jul 2025 124 36 2 0 UA
Jun 2025 145 55 0 0 UA
May 2025 155 59 0 0 UA,YX
Apr 2025 154 28 0 0 UA
Mar 2025 126 24 0 0 UA
Feb 2025 112 15 3 0 UA
Jan 2025 124 13 4 0 YX,UA
Dec 2024 124 22 1 0 UA,YX
Nov 2024 119 22 0 0 UA
Oct 2024 124 13 0 0 UA
Sep 2024 120 27 0 0 UA
Aug 2024 124 42 2 0 UA
Jul 2024 124 36 1 0 UA
Jun 2024 120 26 0 0 UA
May 2024 124 35 0 1 UA
Apr 2024 120 24 1 0 UA
Mar 2024 124 17 0 0 UA
Feb 2024 115 9 0 0 UA
Jan 2024 124 19 15 1 UA

IAD–BOS seasonal on-time pattern

Best: March (88.0%) · weakest: July (71.7%)

70%75%80%85%90% JanFebMarAprMayJunJulAugSepOctNovDec 80%

Strongest calendar month

March

88.0% on-time · ~109 flights/mo

Busiest calendar month

October

~112 flights/mo avg

Weakest calendar month

July

71.7% on-time · ~107 flights/mo

Cancellation Rate

1.1%

34 of 3,043 flights

Diversion Rate

0.1%

2 of 3,043 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

BOS - Boston

Full on-time, delay-cause, and seasonal performance for Boston, MA.

BOS on-time profile

Compare the two airports

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

Compare IAD vs BOS

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: Boston · fleet on-time rank #2883 of 4927.

What the Data Says About IAD to BOS

7,619 tracked flights put the IAD to BOS pairing (Washington to Boston) at a 80.6% on-time rate, squarely in line with the wider network. Delays that do occur run 75.3 minutes on average. Across the 413-mile route and its 9 carriers, the trailing 24 months show 1.1% cancelled and 0.1% diverted (3,043 flights sampled).

The monthly split is wide on this route: Feb 2024 posted the strongest performance at 92% on-time, while Sep 2025 came in at just 58% - a 34-point swing worth factoring into travel timing.

On the multi-year calendar, IAD–BOS peaks in March at 88.0% on-time while October carries the heaviest traffic (~112 flights per month) ; the softest month is July at 71.7%, a 16.3-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does IAD to BOS rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, IAD to BOS ranks #1650 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 BOS? ▼
Flights from Washington to Boston have a 80.6% on-time rate based on 7,619 flights. The average delay is 75.3 minutes. The best recent month was Feb 2024 with 92% on-time.
What is the cancellation rate for IAD to BOS? ▼
Over the last 24 months, 1.1% of flights on this route were cancelled (34 of 3,043 flights) and 0.1% were diverted.
How far is the flight from IAD to BOS? ▼
The flight distance from Washington (IAD) to Boston (BOS) is approximately 413 miles. This route is served by 9 carriers.
When is the best time to fly from IAD to BOS? ▼
The best recent month for on-time performance was Feb 2024 (92% on-time). The worst was Sep 2025 (58% on-time). Consider booking during months with historically better performance.

Airports on this route

IAD Airport

Washington
BOS Airport

Boston
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–BOS data

IAD–BOS is mid-pack at 80.6% on-time; month and carrier mix move more than the corridor headline.

  • Compare IAD and BOS airport profiles: delay causes and top routes differ even on the same corridor. IAD airport
  • If your dates flex, March (88.0% on-time) beats July (71.7%) on this corridor. Seasonal chart
  • 4 other routes post a similar 80.6% 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.