ON TIMEBOARD

SEA → FCA on time

Seattle-Tacoma (Seattle, WA) to Glacier Park (Kalispell, MT). Every scheduled flight, September 2025 to August 2026.

On time
83%
arrived < 15 min late
Cancelled
1.4%
1,045 flights
Typical arrival
−7 min
median vs schedule
When late
+43 min
average delay
Flights / day
3
1 airline

83% of flights from Seattle to Kalispell arrived on time over the past 12 months. That is better than the typical U.S. route. The 9 a.m. departures ran on time 86% of the time; the 1 p.m. ones 76%. 5% 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 → FCA: when a flight was late, it was under 45 minutes late 70% of the time. About 1 in 33 flights landed an hour or more late; 1.4% were cancelled outright.

Share of all 1,045 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
Alaska Airlines1,04583%1.4%−7 min3.1%+43 minHorizon Air 95%, SkyWest 5%

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%8 a.m. departures: too few flights (82 flights)8a9 a.m. departures: 86% on time (194 flights)869a10 a.m. departures: too few flights (72 flights)10a11 a.m. departures: too few flights11anoon departures: too few flights12p1 p.m. departures: 76% on time (119 flights)761p2 p.m. departures: too few flights2p3 p.m. departures: too few flights (35 flights)3p4 p.m. departures: too few flights (91 flights)4p5 p.m. departures: 79% on time (107 flights)795p6 p.m. departures: too few flights6p7 p.m. departures: too few flights7p8 p.m. departures: too few flights (13 flights)8p9 p.m. departures: 83% on time (332 flights)839p
SEA → FCA, 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 → FCA, each airline's last flight of the day was cancelled 1.7% of the time, against 1.2% for its earlier flights (1.5× as often). It arrived 3+ hours late 0.0% of the time (earlier flights: 0.1%). 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 Airlines9:35 p.m.1.7%0.0%1.2%first flight 8:27 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.

If you need to be in FCA tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: April (92%). Worst: August (73%).

40%70%100%Jan: 80% on time (261 flights)80JanFeb: 85% on time (243 flights)85FebMar: 88% on time (265 flights)88MarApr: 92% on time (251 flights)92AprMay: 85% on time (271 flights)85MayJun: 77% on time (288 flights)77JunJul: 81% on time (265 flights)81JulAug: 73% on time (354 flights)73AugSep: 85% on time (358 flights)85SepOct: 89% on time (255 flights)89OctNov: 88% on time (208 flights)88NovDec: 77% on time (230 flights)77Dec

By day of week

DayFlightsOn timeCancelled
Monday15681%0.0%
Tuesday14388%0.0%
Wednesday14484%3.5%
Thursday14378%3.5%
Friday15479%1.3%
Saturday14987%1.3%
Sunday15685%0.6%

Why flights were late

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

Late inbound plane 43%Airline (crew, maintenance, ops) 36%Air traffic & airport (NAS) 14%Severe weather 6%

Cancellations: weather 12 · airline 3

Month by month

60%80%100%Sep 2023Jan 2024Jan 2025Jan 2026Sep 2023: 88% on time, 0.0% cancelledJun 2024: 79% on time, 0.9% cancelledJul 2024: 81% on time, 0.8% cancelledAug 2024: 77% on time, 0.0% cancelledSep 2024: 80% on time, 0.0% cancelledAug 2025: 75% on time, 0.0% cancelledSep 2025: 87% on time, 0.0% cancelledAug 2026: 66% on time, 0.0% cancelled
Share of flights on time, by month (hover a point for cancellations)
SEA → FCA, monthly on-time and cancellation rate.

Worst days in the past year

DateFlightsOn timeCancelled
Mar 13, 202630%2
Feb 19, 202630%0
Jan 3, 202630%2
Jan 14, 202630%3
Aug 9, 202630%0

Questions

How often are flights from SEA to FCA on time?

83% of 1,045 scheduled flights from Seattle, WA to Kalispell, MT arrived within 15 minutes of schedule between September 2025 and August 2026. 1.4% were cancelled.

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

Flights scheduled to leave at 9 a.m. were the most reliable (86% on time). The 1 p.m. departures were the least (76%).

What month has the most delays from SEA to FCA?

August (73% on time). The best month is April (92%), over 2023–2026.

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

Yes. Each airline's last SEA–FCA flight of the day was cancelled 1.7% of the time over the past year, against 1.2% 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.