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Route · IND → SEA · 2020–2025 BTS data

Indianapolis to Seattle

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), IND to SEA (Indianapolis to Seattle) ranks #3621 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

79.2%
On-time
+0.2 pts
vs US avg
58 min
Delay when late
2,321
Flights
#3621 of 4927
Corpus placement

Cancelled

0.7%

Best Month

Jul 2024 84%

Worst Month

Jun 2024 53%

Distance

1,866 mi

Carriers

2

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 41 18 1 0 AS
Nov 2025 38 9 0 0 AS
Oct 2025 48 6 2 0 AS
Sep 2025 51 13 0 0 AS
Aug 2025 59 21 0 0 AS
Jul 2025 61 21 0 1 AS
Jun 2025 60 21 1 0 AS
May 2025 62 16 1 0 AS
Apr 2025 38 10 0 0 AS
Mar 2025 31 7 0 0 AS
Dec 2024 45 5 0 0 AS
Nov 2024 38 5 0 0 AS
Oct 2024 46 3 1 0 AS
Sep 2024 55 16 0 0 AS
Aug 2024 61 19 0 0 AS
Jul 2024 62 10 1 0 AS
Jun 2024 60 28 0 0 AS
May 2024 55 21 0 0 AS
Apr 2024 37 12 0 0 AS
Mar 2024 31 4 1 0 AS
Dec 2023 31 6 0 0 AS
Nov 2023 30 2 0 0 AS
Oct 2023 32 2 0 0 AS
Sep 2023 60 12 0 0 AS

IND–SEA seasonal on-time pattern

Best: October (88.6%) · weakest: December (68.9%)

65%70%75%80%85%90% JanFebMarAprMayJunJulAugSepOctNovDec 68.9%

Strongest calendar month

October

88.6% on-time · ~37 flights/mo

Busiest calendar month

July

~55 flights/mo avg

Weakest calendar month

December

68.9% on-time · ~37 flights/mo

Cancellation Rate

0.7%

8 of 1,132 flights

Diversion Rate

0.1%

1 of 1,132 flights

Explore origin & destination

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

IND - Indianapolis

Full on-time, delay-cause, and seasonal performance for Indianapolis, IN.

IND on-time profile

SEA - Seattle

Full on-time, delay-cause, and seasonal performance for Seattle, WA.

SEA on-time profile

Compare the two airports

See IND and SEA side by side on delays, cancellations, and reliability.

Compare IND vs SEA

Origin-hub reliability standing

Mid-pack among IND departures

From IND, this corridor sits with 20 other 75–85% on-time routes out of 32 tracked departures, not the hub's reliability leaders (12 at ≥85%) and not the softest ( 0 below 75%). Destination: Seattle · fleet on-time rank #3445 of 4927.

What the Data Says About IND to SEA

2,321 tracked flights put the IND to SEA pairing (Indianapolis to Seattle) at a 79.2% on-time rate, squarely in line with the wider network. Delays that do occur run 58.2 minutes on average. Across the 1,866-mile route and its 2 carriers, the trailing 24 months show 0.7% cancelled and 0.1% diverted (1,132 flights sampled).

The monthly split is wide on this route: Jul 2024 posted the strongest performance at 84% on-time, while Jun 2024 came in at just 53% - a 31-point swing worth factoring into travel timing.

On the multi-year calendar, IND–SEA peaks in October at 88.6% on-time while July carries the heaviest traffic (~55 flights per month) ; the softest month is December at 68.9%, a 19.7-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does IND to SEA rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, IND to SEA ranks #3621 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 IND to SEA? ▼
Flights from Indianapolis to Seattle have a 79.2% on-time rate based on 2,321 flights. The average delay is 58.2 minutes. The best recent month was Jul 2024 with 84% on-time.
What is the cancellation rate for IND to SEA? ▼
Over the last 24 months, 0.7% of flights on this route were cancelled (8 of 1,132 flights) and 0.1% were diverted.
How far is the flight from IND to SEA? ▼
The flight distance from Indianapolis (IND) to Seattle (SEA) is approximately 1,866 miles. This route is served by 2 carriers.
When is the best time to fly from IND to SEA? ▼
The best recent month for on-time performance was Jul 2024 (84% on-time). The worst was Jun 2024 (53% on-time). Consider booking during months with historically better performance.

Airports on this route

IND Airport

Indianapolis
SEA Airport

Seattle
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 IND–SEA data

IND–SEA is mid-pack at 79.2% on-time; month and carrier mix move more than the corridor headline.

  • Compare IND and SEA airport profiles: delay causes and top routes differ even on the same corridor. IND airport
  • If your dates flex, October (88.6% on-time) beats December (68.9%) on this corridor. Seasonal chart
  • 4 other routes post a similar 79.2% 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.