ON TIMEBOARD

SEA → IND on time

Seattle-Tacoma (Seattle, WA) to Indianapolis (Indianapolis, IN). Every scheduled flight, September 2025 to August 2026.

On time
79%
arrived < 15 min late
Cancelled
1.2%
568 flights
Typical arrival
−7 min
median vs schedule
When late
+44 min
average delay
Flights / day
2
1 airline

79% of flights from Seattle to Indianapolis arrived on time over the past 12 months. That is about the typical U.S. route. The 10 a.m. departures ran on time 81% of the time; the 10 p.m. ones 73%. 6% of flights arrived more than an hour late or not at all.

How late?

The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for SEA → IND: when a flight was late, it was under 45 minutes late 67% of the time. About 1 in 23 flights landed an hour or more late; 1.2% were cancelled outright.

Share of all 568 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
Alaska Airlines56879%1.2%−7 min4.4%+44 minAlaska Airlines

Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.

Best time of day to fly

On-time rate by scheduled departure hour (local time at SEA). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%9 a.m. departures: too few flights (83 flights)9a10 a.m. departures: 81% on time (150 flights)8110a11 a.m. departures: 78% on time (120 flights)7811anoon departures: too few flights12p1 p.m. departures: too few flights1p2 p.m. departures: too few flights2p3 p.m. departures: too few flights3p4 p.m. departures: too few flights4p5 p.m. departures: too few flights5p6 p.m. departures: too few flights6p7 p.m. departures: too few flights7p8 p.m. departures: too few flights8p9 p.m. departures: too few flights (53 flights)9p10 p.m. departures: 73% on time (162 flights)7310p
SEA → IND, share of flights arriving on time, by departure hour. Hours with under 100 flights are greyed out.
82%+ on time76–82%68–76%under 68%too few flights

Last flight of the day

On SEA → IND, each airline's last flight of the day was cancelled 0.0% of the time, against 0.9% for its earlier flights, so here the last flight is actually the safer one. It arrived 3+ hours late 0.0% of the time (earlier flights: 0.0%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.

AirlineLast departureLast: cancelledLast: 3h+ lateEarlier: cancelledNext morning
Alaska Airlines10:39 p.m.0.0%0.0%0.9%first flight 9:09 a.m.

Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.

By month

Each calendar month pooled over 2023–2026. Best: November (94%). Worst: July (67%).

40%70%100%Jan: too few flights (81 flights)JanFeb: too few flights (74 flights)FebMar: 75% on time (101 flights)75MarApr: 78% on time (128 flights)78AprMay: 70% on time (179 flights)70MayJun: 68% on time (180 flights)68JunJul: 67% on time (184 flights)67JulAug: 70% on time (181 flights)70AugSep: 68% on time (167 flights)68SepOct: 85% on time (124 flights)85OctNov: 94% on time (108 flights)94NovDec: 74% on time (117 flights)74Dec

By day of week

DayFlightsOn timeCancelled
Monday89——
Tuesday69——
Wednesday77——
Thursday84——
Friday89——
Saturday72——
Sunday88——

Why flights were late

Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.

Airline (crew, maintenance, ops) 55%Late inbound plane 26%Air traffic & airport (NAS) 18%

Cancellations: airline 4 · weather 3

Month by month

Not enough months with data to draw a trend.

Flight numbers on this route

Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.

FlightDepartsFlightsOn timeCancelledTypical arrivalOperated by
AS 5009:09 a.m.32679%1.2%−7 minAlaska Airlines
AS 62410:39 p.m.14778%0.0%−9 minAlaska Airlines

Questions

How often are flights from SEA to IND on time?

79% of 568 scheduled flights from Seattle, WA to Indianapolis, IN arrived within 15 minutes of schedule between September 2025 and August 2026. 1.2% were cancelled.

What is the best time of day to fly SEA to IND?

Flights scheduled to leave at 10 a.m. were the most reliable (81% on time). The 10 p.m. departures were the least (73%).

What month has the most delays from SEA to IND?

July (67% on time). The best month is November (94%), over 2023–2026.

Is the last flight of the day from SEA to IND more likely to be cancelled?

No, the opposite. Each airline's last SEA–IND flight of the day was cancelled 0.0% of the time over the past year, against 0.9% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.

Related

Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.