Carrier route record
DLFLL→SEA
Delta Air Lines · Fort Lauderdale to Seattle
- Flights
- 364
- Period
- September 2025 to August 2026
- Share of route
- 44%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on FLL to SEA lands a B, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 364 flights, with a median arrival 7 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Delta on FLL to SEA from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.5%
Arrivals under 15 minutes late, of 356 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
1.37%
National rate is 1.89%
Whole route
73.3%
Every carrier on FLL to SEA, 826 flights
These figures cover 364 flights between September 2025 and August 2026. The median arrival is 7 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Carrier by carrier
Delta against every carrier on FLL to SEA
Delta flew 364 of the 826 flights on FLL to SEA, about 44% of it. Its 79.5% on time is 6 points better than the route as a whole, which runs 73.3%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Delta at 79.5% to Alaska at 68.4%.
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 Lines (this page)thin sample | 364 | 79.5% | 58 min | 1.37% | B |
| Alaska Airlines | 462 | 68.4% | 50 min | 1.08% | C |
Flight by flight
Delta flight numbers on FLL to SEA
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Departure window
When Delta 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 364 flights.
- 5am–8am—
- 8am–11am329 flights79.2%
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm35 flights82.4%
- 8pm–5am—
Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is the strongest at 82.4% on time. The full set of windows spans 3 points.
Across the year
Delta on FLL to SEA through the year
- Jul–Sep 202530 flights—
- Oct–Dec 202591 flights71.9%
- Jan–Mar 202690 flights65.5%
- Apr–Jun 202691 flights90.1%
- Jul–Sep 202662 flights95.0%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 79.5% on time across 364 flights.
Delta on FLL to SEA did not run the same all year. Its best quarter was Jul–Sep 2026 at 95.0% on time and its weakest Jan–Mar 2026 at 65.5%, a swing of 30 points on roughly 91 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Thursday is the strongest day at 86.0% on time and Tuesday the weakest at 68.6%, a spread of 17 points.
Arrival by arrival
How late Delta on FLL to SEA runs when it is late
Delta on FLL to SEA often beats the schedule: 130 of 356 completed flights, 37%, arrived 15 minutes or more early. The 73 late arrivals split 29 under half an hour, 27 between 30 and 60 minutes, and 17 an hour or more.
- 15+ min early130 flights36.5%
- Within 15 min153 flights43.0%
- 15–29 min late29 flights8.1%
- 30–59 min late27 flights7.6%
- 1–2 hours late13 flights3.7%
- 2+ hours late4 flights1.1%
Scale runs 0% to 100%.
Share of 356 completed flights by arrival against schedule.
15 of 66 late departures made up the time and arrived on time, 23% of them. In the other direction, 22 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 Delta on FLL to SEA
The latest arrival of the period was on 18 October 2025, 10 hours 5 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 18 October 2025 | 10 hours 5 minutes | Late-arriving aircraft |
| 22 February 2026 | 5 hours 58 minutes | Late-arriving aircraft |
| 12 April 2026 | 5 hours 13 minutes | Carrier |
| 9 December 2025 | 2 hours 12 minutes | Late-arriving aircraft |
| 29 August 2026 | 1 hour 54 minutes | Extreme weather |
Delay causes
Why Delta runs late on this route
Late-arriving aircraft accounts for 55% of the 4,240 delay minutes carriers reported here, and the remaining four split what is left.
- 55%Late-arriving aircraft
- 21%National Airspace System
- 19%Carrier
- 5%Extreme weather
55% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4,240 reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 4,240 reported delay minutes.
Cancellations sit at 1.37% against a national 1.89%, which is ordinary. Diversions add another 0.82%.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 4.8% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
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 75.3% on time across 364 flights, 4 points below 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 4 points of difference.
One caution: this is a thin sample. 364 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 Delta on FLL to SEA
Put together: treat all of this as provisional. 364 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 79.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 356 completed flights over 12 months sit behind that.
Related
Where to go next
- FLL to SEA, every carrier
- Delta on SEA to FLL, the return leg
- Alaska Airlines on FLL to SEA68.4%
- Delta Air Lines 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
- How to read this site: grades, sample sizes, and honest caveats
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.