Carrier route record
ASFLL→SEA
Alaska Airlines · Fort Lauderdale to Seattle
- Flights
- 462
- Period
- September 2025 to August 2026
- Share of route
- 56%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on FLL to SEA sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.3%. The late ones land about 50 minutes behind schedule. That rests on 462 flights, with a median arrival 2 minutes late.
The national on-time rate over the same period is 77.3%, so Alaska on FLL to SEA runs 9 points behind the country as a whole. Across a thousand flights that is about 89 extra late arrivals.
Key figures
On time
68.4%
Arrivals under 15 minutes late, of 449 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
1.08%
National rate is 1.89%
Whole route
73.3%
Every carrier on FLL to SEA, 826 flights
These figures cover 462 flights between September 2025 and August 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
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Carrier by carrier
Alaska against every carrier on FLL to SEA
Alaska flew 462 of the 826 flights on FLL to SEA, most of the route. Its 68.4% on time is 5 points worse than the route as a whole, which runs 73.3%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Delta at 79.5% to Alaska at 68.4%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Linesthin sample | 364 | 79.5% | 58 min | 1.37% | B |
| Alaska Airlines (this page) | 462 | 68.4% | 50 min | 1.08% | C |
Flight by flight
Alaska flight numbers on FLL to SEA
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Departure window
When Alaska runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 462 flights.
- 5am–8am109 flights68.3%
- 8am–11am—
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm353 flights68.4%
- 8pm–5am—
Scale runs 60% to 75%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is the strongest at 68.4% on time. The full set of windows spans half a point.
Across the year
Alaska on FLL to SEA through the year
December is the weak month at 48.3% on time, against 90.0% in May. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. December was the busiest month here, with 62 flights.
Across the week, Thursday is the strongest day at 77.3% on time and Sunday the weakest at 48.4%, a spread of 29 points.
Arrival by arrival
How late Alaska on FLL to SEA runs when it is late
The 142 late arrivals split 66 under half an hour, 49 between 30 and 60 minutes, and 27 an hour or more.
- 15+ min early94 flights20.9%
- Within 15 min213 flights47.4%
- 15–29 min late66 flights14.7%
- 30–59 min late49 flights10.9%
- 1–2 hours late17 flights3.8%
- 2+ hours late10 flights2.2%
Scale runs 0% to 100%.
Share of 449 completed flights by arrival against schedule.
24 of 102 late departures made up the time and arrived on time, 24% of them. In the other direction, 64 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at SEA.
The worst days
Worst days for Alaska on FLL to SEA
The latest arrival of the period was on 17 March 2026, 10 hours 18 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 17 March 2026 | 10 hours 18 minutes | Late-arriving aircraft |
| 22 December 2025 | 5 hours 12 minutes | Carrier |
| 15 January 2026 | 3 hours 51 minutes | Late-arriving aircraft |
| 12 February 2026 | 3 hours 9 minutes | Late-arriving aircraft |
| 13 March 2026 | 2 hours 48 minutes | Late-arriving aircraft |
Delay causes
Why Alaska runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,157 reported delay minutes.
- 40%Late-arriving aircraft
- 34%National Airspace System
- 19%Carrier
- 7%Extreme weather
- 0%Security
40% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 7,157 reported delay minutes here, that single category outweighs weather by 6 to one. The split is drawn from 7,157 reported delay minutes.
34% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 2,452 minutes out of 7,157, against a national NAS share of 21%.
Cancellations sit at 1.08% against a national 1.89%, which is ordinary. Diversions add another 1.73%.
Connections and stage length
What a delay here costs
6.0% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 50 minutes, which a normal layover absorbs.
At 2,717 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 81.1% on time across 462 flights, 13 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 13 points of difference.
One caution: this is a thin sample. 462 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Alaska on FLL to SEA
Put together: treat all of this as provisional. 462 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 68.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 449 completed flights over 12 months sit behind that.
Related
Where to go next
- FLL to SEA, every carrier
- Alaska on SEA to FLL, the return leg
- Delta Air Lines on FLL to SEA79.5%
- Alaska Airlines network-wide record
- Fort Lauderdale-Hollywood International (FLL) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Why the first flight of the morning is statistically safest
- Worst months to fly in the US, ranked by the data
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.