Flight number record
DL 356
Delta Air Lines · Fort Lauderdale to Seattle
- Route
- FLL → SEA
- Departs
- 08:35
- Flights
- 255
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 356, check with Delta Air Lines.
DL 356 lands a B, 5 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 255 flights, with a median arrival 8 minutes early.
Set against the rest of the country, DL 356's record is 5 points better than the US average of 77.3%. That gap is worth roughly 46 fewer late arrivals for every thousand flights.
Key figures
On time
81.9%
Arrivals under 15 minutes late, of 249 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
1.57%
National rate is 1.89%
1 hour+ late
4.4%
National rate is 8.3%
These figures cover 255 flights between September 2025 and August 2026. The median arrival is 8 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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Schedule
When DL 356 flies
DL 356 flies FLL to SEA without a single fixed slot. Its most common scheduled departure was 08:35, used on 62 of 255 flights, with 08:50 (31 flights) and 07:55 (31 flights) next.
- Departs 08:3562 flights24.3%
- Departs 08:5031 flights12.2%
- Departs 07:5531 flights12.2%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 08:35 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and DL 356 runs 2 points worse at 81.9%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
DL 356 next to FLL to SEA
Every carrier on FLL to SEA combined arrived on time 73.3% of the time across 826 flights, so DL 356 is 9 points ahead of it. Across its whole network Delta Air Lines managed 81.1%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 356thin sample | 255 | 81.9% | 56 min | 1.57% | B |
| All Delta Air Lines on FLL–SEAthin sample | 364 | 79.5% | 58 min | 1.37% | B |
| All carriers on FLL–SEA | 826 | 73.3% | 53 min | 1.21% | C |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 356 quarter by quarter
DL 356 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 85 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.
- Oct–Dec 202512 flights—
- 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.
By weekday, DL 356 did best on Monday at 94.4% on time and worst on Friday at 71.4%. Each day rests on about 36 flights, so a gap of 23 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 356 runs when it is late
DL 356 often beats the schedule: 92 of 249 completed flights, 37%, arrived 15 minutes or more early. The 45 late arrivals split 18 under half an hour, 16 between 30 and 60 minutes, and 11 an hour or more.
- 15+ min early92 flights36.9%
- Within 15 min112 flights45.0%
- 15–29 min late18 flights7.2%
- 30–59 min late16 flights6.4%
- 1–2 hours late9 flights3.6%
- 2+ hours late2 flights0.8%
Scale runs 0% to 100%.
Share of 249 completed flights by arrival against schedule.
11 of 44 late departures made up the time and arrived on time, 25% of them. 12 flights left on time and still arrived late.
The worst days
Worst days for DL 356
The latest arrival of the period was on 22 February 2026, 5 hours 58 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The five worst days are spread across February, April, August and January, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 22 February 2026 | 5 hours 58 minutes | Late-arriving aircraft |
| 12 April 2026 | 5 hours 13 minutes | Carrier |
| 29 August 2026 | 1 hour 54 minutes | Extreme weather |
| 14 January 2026 | 1 hour 44 minutes | Late-arriving aircraft |
| 3 January 2026 | 1 hour 38 minutes | Carrier |
Delay causes
Why DL 356 runs late
Late-arriving aircraft accounts for 47% of the 2,516 delay minutes carriers reported here, and the remaining four split what is left.
- 47%Late-arriving aircraft
- 26%Carrier
- 21%National Airspace System
- 6%Extreme weather
47% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 2,516 reported delay minutes here, that single category outweighs weather by 8 to one. The split is drawn from 2,516 delay minutes reported on DL 356.
Cancellations sit at 1.57% against a national 1.89%, which is ordinary. Diversions add another 0.78%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 4.4% 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 same number turns up on six other city pairs in the data, including AGS to ATL (21), ATL to AGS (21) and SAN to JFK (16), but none flew often enough under DL 356 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to FLL to SEA only.
One caution: this is a thin sample. 255 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 DL 356
For a booking, read DL 356 as 81.9% on time with 1.57% cancelled over 255 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- FLL to SEA, every carrier and departure
- SEA to FLL, the return direction
- Alaska Airlines 517 on the same route66.8%
- Fort Lauderdale-Hollywood International (FLL) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Delta Air Lines on-time record
- Every Delta Air Lines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Delta Air Lines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.