Route profile
IND→SEA
Flight reliability, delays and best times to fly from Indianapolis to Seattle, 1,866 miles.
Right now
Aviation weather is not currently a factor.
Weather conditions are strongly associated with delays and cancellations.
Route reliability
July 2023 – July 2026
Better than 46% of comparable major US routes (4,598 compared)
Calculated from 1,685 flights. How this is calculated · What counts as on time
IND → SEA arrives on time 75.6% of the time; the return trip, SEA → IND, arrives on time 74.2% of the time.
IND → SEA spends 27.8 minutes on the ground on a 1,866-mile trip: 16.3 minutes from pushback to wheels-up at IND and 11.5 minutes from touchdown to gate at SEA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route has stayed remarkably steady year over year, a smaller swing than 93% of 5,368 comparable routes.
74.8% on time over the most recent 12 months (2025-08 to 2026-07), against 75.2% in the 12 months before (2024-08 to 2025-07), virtually unchanged.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 5,368 in the comparison.
What sets this route apart
Where IND to SEA differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
IND to SEA struggles most at 7 AM: 79.0% of its flights scheduled then arrive on time, 7.9 points behind the 86.9% on routes of similar length at the same hour. Against all other routes the gap is 8.8 points.
IND to SEA is at its best against routes of similar length for flights scheduled at 6 PM: 74.8% arrive on time, 4.8 points ahead of the 70.0% those routes manage at that hour. Against all other routes the gap is 6.2 points.
Saturday is the day IND to SEA slips furthest against routes of similar length, 73.0% on time where they average 78.9%, 5.9 points lower. Against all other routes the gap is 6.1 points.
In June, IND to SEA runs 11.9 points below routes of similar length, 60.7% on time to 72.6%. Against all other routes the gap is 12 points.
July is kinder to IND to SEA than to routes of similar length: 78.3% on time against 70.1%, 8.2 points better. Against all other routes the gap is 8.6 points.
IND to SEA against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 7 AM departures | 79.0% | routes of similar length | 86.9% | −7.9 pts | 529 here, 115,651 there |
| Hour: 6 PM departures | 74.8% | routes of similar length | 70.0% | +4.8 pts | 807 here, 65,863 there |
| Weekday: Saturday | 73.0% | routes of similar length | 78.9% | −5.9 pts | 226 here, 168,391 there |
| Month: June | 60.7% | routes of similar length | 72.6% | −11.9 pts | 178 here, 109,751 there |
| Month: July | 78.3% | routes of similar length | 70.1% | +8.2 pts | 244 here, 147,276 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
41 min late
against a median of 2 min early
Percentiles over 1,685 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SEA after arriving from IND.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 45% | Likely to miss |
| 45 min | 23% | High risk |
| 60 min | 13% | Some risk |
| 90 min | 6.4% | Some risk |
| 120 min | 3.4% | 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 1.36% of the time and diverts 0.06% of the time, which a late arrival never shows up in.
Chance of missing is the share of 1,661 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 41 minutes late (90th-percentile gate arrival delay), over 1,685 operations.
Any other layover length: connection checker.
Why IND → SEA 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 IND → SEA. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on IND → SEA, at 54.7%: 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 | 1,685 | 75.6% | 1.36% | -2 min | 6.5% |
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Saturday the least, a gap of 4.8 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 74.8% against 75.2% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 1,685 IND → SEA 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