Flight number record

DL 668

Delta Air Lines · New York to San Francisco

Route: JFK → SFO
Departs: 07:00
Flights: 359
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 668, check with Delta Air Lines.

DL 668 sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 359 flights, with a median arrival 6 minutes early.

On time

74.1%

Arrivals under 15 minutes late, of 351 completed flights

Avg delay

60 min

Across delayed arrivals only, not all flights

Cancelled

1.95%

National rate is 1.81%

1 hour+ late

6.8%

National rate is 8.1%

These figures cover 359 flights between July 2025 and June 2026. The median arrival is 6 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.

Schedule

When DL 668 flies

DL 668 flies JFK to SFO without a single fixed slot. Its most common scheduled departure was 07:00, used on 278 of 359 flights. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 07:00278 flights77.4%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.

A 07:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 668 runs 15 points worse at 74.1%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

DL 668 next to JFK to SFO

Every carrier on JFK to SFO combined arrived on time 74.1% of the time across 6,730 flights, so DL 668 is about level with it. Delta flew 2,229 flights on the same city pair under all its flight numbers, including this one, and those ran 71.3% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 8 points.

DL 668 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 668thin sample	359	74.1%	60 min	1.95%	C
All Delta Air Lines on JFK–SFO	2,229	71.3%	70 min	1.48%	C
All carriers on JFK–SFO	6,730	74.1%	71 min	1.92%	C
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 668 quarter by quarter

DL 668 did not run the same all year. Its best quarter was Jul–Sep 2025 at 90.1% on time and its weakest Apr–Jun 2026 at 64.4%, a swing of 26 points on roughly 90 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 202592 flights90.1%
Oct–Dec 202589 flights67.0%
Jan–Mar 202689 flights74.1%
Apr–Jun 202689 flights64.4%

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, DL 668 did best on Wednesday at 82.4% on time and worst on Monday at 67.3%. Each day rests on about 51 flights, so a gap of 15 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 668 runs late

One category carries most of the weight here. Carrier accounts for 55% of the 5,435 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Carrier
55%
National Airspace System
43%
Extreme weather
1%
Late-arriving aircraft
1%

The largest share of delay minutes, 55%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 2,970 of the 5,435 delay minutes reported here. The split is drawn from 5,435 delay minutes reported on DL 668.

Cancellations sit at 1.95% against a national 1.81%, which is ordinary. Diversions add another 0.28%.

Connections and routes

What a delay on this flight costs

6.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

At 2,586 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.

DL 668 is not only a JFK to SFO flight. It also flew SFO to JFK (346 flights, 76.0% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.

One caution: this is a thin sample. 359 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.

Other routes flown as DL 668
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
SFO to JFKthin sample	346	76.0%	81 min	3.18%	B−

What to do with this

Booking DL 668

For a booking, read DL 668 as 74.1% on time with 1.95% cancelled over 359 flights. Those are rates from the past twelve months, not a forecast for any particular day.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures