Flight number record
DL 340
Delta Air Lines · Seattle to Kailua-Kona
- Route
- SEA → KOA
- Departs
- 14:30
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 340, check with Delta Air Lines.
DL 340 lands a B, about a point worse than the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by roughly 45 minutes on average. That rests on 365 flights, with a median arrival 5 minutes early.
Key figures
On time
76.1%
Arrivals under 15 minutes late, of 356 completed flights
Avg delay
47 min
Across delayed arrivals only, not all flights
Cancelled
2.19%
National rate is 1.89%
1 hour+ late
4.8%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 5 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 340 flies
DL 340 flies SEA to KOA without a single fixed slot. Its most common scheduled departure was 14:30, used on 117 of 365 flights, with 14:20 (69 flights) and 15:25 (48 flights) next.
- Departs 14:30117 flights32.1%
- Departs 14:2069 flights18.9%
- Departs 15:2548 flights13.2%
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 14:30 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and DL 340 runs 4 points better at 76.1%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
DL 340 next to SEA to KOA
Every carrier on SEA to KOA combined arrived on time 74.5% of the time across 1,410 flights, so DL 340 is 2 points ahead of it. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 5 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 340 | 365 | 76.1% | 47 min | 2.19% | B |
| All Delta Air Lines on SEA–KOA | 365 | 76.1% | 47 min | 2.19% | B |
| All carriers on SEA–KOA | 1,410 | 74.5% | 50 min | 1.42% | C |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 340 quarter by quarter
DL 340 did not run the same all year. Its best quarter was Jul–Sep 2025 at 90.0% on time and its weakest Jan–Mar 2026 at 65.5%, a swing of 25 points on roughly 73 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.
- Jul–Sep 202530 flights90.0%
- Oct–Dec 202592 flights78.4%
- Jan–Mar 202690 flights65.5%
- Apr–Jun 202691 flights84.6%
- Jul–Sep 202662 flights68.3%
Scale runs 55% to 95%.
By weekday, DL 340 did best on Wednesday at 88.2% on time and worst on Friday at 67.3%. Each day rests on about 52 flights, so a gap of 21 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 340 runs when it is late
DL 340 often beats the schedule: 90 of 356 completed flights, 25%, arrived 15 minutes or more early. Most of the lateness is short. 45 of the 85 late arrivals were under half an hour behind, and 17 reached an hour or more.
- 15+ min early90 flights25.3%
- Within 15 min181 flights50.8%
- 15–29 min late45 flights12.6%
- 30–59 min late23 flights6.5%
- 1–2 hours late12 flights3.4%
- 2+ hours late5 flights1.4%
Scale runs 0% to 100%.
Share of 356 completed flights by arrival against schedule.
14 of 57 late departures made up the time and arrived on time, 25% of them. In the other direction, 42 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 KOA.
The worst days
Worst days for DL 340
The latest arrival of the period was on 19 December 2025, 6 hours 33 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 19 December 2025 | 6 hours 33 minutes | Carrier |
| 7 December 2025 | 3 hours 28 minutes | Late-arriving aircraft |
| 24 April 2026 | 3 hours 3 minutes | Carrier |
| 10 February 2026 | 2 hours 39 minutes | Carrier |
| 11 May 2026 | 2 hours 3 minutes | Carrier |
Delay causes
Why DL 340 runs late
National Airspace System accounts for 43% of the 3,951 delay minutes carriers reported here, and the remaining four split what is left.
- 43%National Airspace System
- 41%Carrier
- 16%Late-arriving aircraft
The largest share of delay minutes, 41%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,624 of the 3,951 delay minutes reported here. The split is drawn from 3,951 delay minutes reported on DL 340.
Cancellations sit at 2.19% against a national 1.89%, which is ordinary. Diversions add another 0.27%.
Connections and routes
What a delay on this flight 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 2,688 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 one other city pair in the data, including KOA to SEA (17), but none flew often enough under DL 340 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to KOA only.
One caution: this is a thin sample. 365 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 340
For a booking, read DL 340 as 76.1% on time with 2.19% cancelled over 365 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- SEA to KOA, every carrier and departure
- KOA to SEA, the return direction
- Alaska Airlines 238 on the same route77.0%
- 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
- Worst months to fly in the US, ranked by the data
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.