Route profile
SEA→IND
Flight reliability, delays and best times to fly from Seattle to Indianapolis, 1,866 miles.
Right now
Weather conditions are strongly associated with delays and cancellations.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 57% of comparable major US routes (4,598 compared)
Calculated from 1,686 flights. How this is calculated · What counts as on time
SEA → IND arrives on time 74.2% of the time; the return trip, IND → SEA, arrives on time 75.6% of the time.
SEA → IND spends 27.1 minutes on the ground on a 1,866-mile trip: 21.8 minutes from pushback to wheels-up at SEA and 5.3 minutes from touchdown to gate at IND.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where SEA to IND differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SEA to IND struggles most at 10 AM: 73.2% of its flights scheduled then arrive on time, 6.1 points behind the 79.3% on routes of similar length at the same hour. Against all other routes the gap is 9.5 points.
Saturday is the day SEA to IND slips furthest against routes of similar length, 69.5% on time where they average 78.9%, 9.4 points lower. Against all other routes the gap is 9.6 points.
In September, SEA to IND runs 14.3 points below routes of similar length, 68.3% on time to 82.6%. Against all other routes the gap is 14.1 points.
SEA to IND against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 10 AM departures | 73.2% | routes of similar length | 79.3% | −6.1 pts | 907 here, 71,131 there |
| Weekday: Saturday | 69.5% | routes of similar length | 78.9% | −9.4 pts | 213 here, 168,404 there |
| Month: September | 68.3% | routes of similar length | 82.6% | −14.3 pts | 167 here, 98,112 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,866 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
37 min late
against a median of 2 min early
Percentiles over 1,686 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at IND after arriving from SEA.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 45% | Likely to miss |
| 45 min | 25% | High risk |
| 60 min | 13% | Some risk |
| 90 min | 4.9% | Low risk |
| 120 min | 2.0% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.07% of the time and diverts 0.24% of the time, which a late arrival never shows up in.
Chance of missing is the share of 1,664 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 37 minutes late (90th-percentile gate arrival delay), over 1,686 operations.
Any other layover length: connection checker.
Why SEA → IND runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for SEA → IND. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on SEA → IND, at 41.1%: flights here mostly leave late because the plane came in late.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Alaska Airlines | 1,686 | 74.2% | 1.07% | -2 min | 5.0% |
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| AS500 Alaska Airlines | 10:42 AM | 1,066 | 73.9% |
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Saturday the least, a gap of 8.6 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 77.3% against 71.1% in the 12 months before — improving by 6.2 percentage points.
Data and methodology
Calculated by FlyerIntel from 1,686 SEA → IND flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed