Route profile
FLL→SEA
Flight reliability, delays and best times to fly from Fort Lauderdale to Seattle, 2,717 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 25% of comparable major US routes (4,598 compared)
Calculated from 2,714 flights. How this is calculated · What counts as on time
FLL → SEA arrives on time 72.7% of the time; the return trip, SEA → FLL, arrives on time 81.2% of the time, an 8.4-point gap between the two directions of the same city pair.
FLL → SEA spends 33.9 minutes on the ground on a 2,717-mile trip: 21.6 minutes from pushback to wheels-up at FLL and 12.3 minutes from touchdown to gate at SEA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where FLL to SEA differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
FLL to SEA is at its best against routes of similar length for flights scheduled at 10 AM: 85.4% arrive on time, 9.1 points ahead of the 76.3% those routes manage at that hour.
FLL to SEA struggles most at 8 AM: 74.2% of its flights scheduled then arrive on time, 9.1 points behind the 83.3% on routes of similar length at the same hour. Against all other routes the gap is 11.7 points.
Sunday is the day FLL to SEA slips furthest against routes of similar length, 65.0% on time where they average 76.1%, 11.1 points lower. Against all other routes the gap is 9.8 points.
In December, FLL to SEA runs 14.1 points below routes of similar length, 63.8% on time to 77.9%. Against all other routes the gap is 15 points.
Alaska Airlines’ flights on FLL to SEA arrive on time 70.7% of the time, 5.3 points below the 76.0% it manages on its routes of similar length. Against all other routes the gap is 7.3 points.
FLL to SEA against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 10 AM departures | 85.4% | routes of similar length | 76.3% | +9.1 pts | 199 here, 33,209 there |
| Hour: 8 AM departures | 74.2% | routes of similar length | 83.3% | −9.1 pts | 283 here, 76,148 there |
| Weekday: Sunday | 65.0% | routes of similar length | 76.1% | −11.1 pts | 377 here, 101,332 there |
| Month: December | 63.8% | routes of similar length | 77.9% | −14.1 pts | 271 here, 56,212 there |
| Airline: Alaska Airlines | 70.7% | routes of similar length | 76.0% | −5.3 pts | 1,527 here, 140,143 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 2,717 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.
Why FLL → SEA flights are cancelled
July 2023 – July 2026
FLL → SEA cancelled 52 of 2,714 scheduled flights — about 1 in every 52. The reason filed most often was the airline, 82.7% of the cancellations coded on this route — about 1 in every 63 scheduled flights.
Share of cancellations
Of 52 cancelled departures carrying a reason code.
What each reason means
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
43 cancellations, 82.7% of the total.
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
9 cancellations, 17.3% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
0 cancellations, 0.0% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. With only one or two carriers on the route, the split mostly reflects how they file. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
52 coded cancellations were recorded on FLL → SEA; the section appears from 50.
When it goes wrong
July 2023 – July 2026
48 min late
against a median of 2 min early
Percentiles over 2,714 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SEA after arriving from FLL.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 45% | Likely to miss |
| 45 min | 26% | High risk |
| 60 min | 16% | High risk |
| 90 min | 7.4% | Some risk |
| 120 min | 4.4% | 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 1.92% of the time and diverts 1.18% of the time, which a late arrival never shows up in.
Chance of missing is the share of 2,630 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 48 minutes late (90th-percentile gate arrival delay), over 2,714 operations.
Any other layover length: connection checker.
Best time to fly
FLL → SEA flights departing 9 AM–12 PM arrived on time 85.4% of the time, against 67.4% for 3–6 PM departures, a gap of 18.0 percentage points.
By departure window
By departure hour
- 12 AM to 6 AM: too few flights to score
- 7 AM: 76.2% on time from 495 flights
- 8 AM: 74.2% on time from 290 flights
- 9 AM: too few flights to score
- 10 AM: 85.4% on time from 206 flights
- 11 AM to 4 PM: too few flights to score
- 5 PM: 67.4% on time from 196 flights
- 6 PM: 70.3% on time from 1,525 flights
- 7 PM to 11 PM: too few flights to score
Why FLL → 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 FLL → SEA. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on FLL → SEA, at 40.1%: flights here mostly leave late because the plane came in late, and the day shows it: 9 AM–12 PM departures arrived on time 85.4% of the time and 3–6 PM departures 67.4%.
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 | 1,591 | 70.7% | 2.45% | 0 min | 6.9% |
| Delta Air Lines | 1,123 | 75.5% | 1.16% | -6 min | 8.3% |
Alaska Airlines flew 58.6% of the 2,714 flights listed. Alaska Airlines cancelled 2.45% of its flights here against 1.16% for Delta Air Lines.
Delta Air Lines arrived on time 4.8 percentage points more often than Alaska Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| AS517 Alaska Airlines | 10:00 AM | 1,047 | 68.8% |
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Sunday the least, a gap of 11.0 percentage points.
By month
- Jan: 70.5%
- Feb: 71.4%
- Mar: 68.4%
- Apr: 71.0%
- May: 78.4%
- Jun: 75.6%
- Jul: 71.1%
- Aug: 65.9%
- Sep: 74.9%
- Oct: 87.6%
- Nov: 78.3%
- Dec: 63.8%
December is historically the weakest month and October the strongest, a spread of 23.8 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 71.1% against 73.3% in the 12 months before — declining by 2.2 percentage points.
Data and methodology
Calculated by FlyerIntel from 2,714 FLL → 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