Flight number record

DL 1421

Delta Air Lines · Los Angeles to San Francisco

Route: LAX → SFO
Departs: 06:30
Flights: 352
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1421, check with Delta Air Lines.

DL 1421 earns an A. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 17 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 352 flights, with a median arrival 13 minutes early.

Set against the rest of the country, DL 1421's record is 17 points better than the US average of 77.6%. That gap is worth roughly 171 fewer late arrivals for every thousand flights.

On time

94.7%

Arrivals under 15 minutes late, of 342 completed flights

Avg delay

66 min

Across delayed arrivals only, not all flights

Cancelled

2.84%

National rate is 1.81%

1 hour+ late

2.0%

National rate is 8.1%

These figures cover 352 flights between July 2025 and June 2026. The median arrival is 13 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 1421 flies

DL 1421 flies LAX to SFO without a single fixed slot. Its most common scheduled departure was 06:30, used on 149 of 352 flights, with 06:00 (94 flights) and 07:00 (57 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 06:30149 flights42.3%
Departs 06:0094 flights26.7%
Departs 07:0057 flights16.2%

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 06:30 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 1421 runs 5 points better at 94.7%. 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 1421 next to LAX to SFO

Every carrier on LAX to SFO combined arrived on time 64.8% of the time across 11,013 flights, so DL 1421 is 30 points ahead of it. Delta flew 2,373 flights on the same city pair under all its flight numbers, including this one, and those ran 65.2% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 13 points.

DL 1421 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1421thin sample	352	94.7%	66 min	2.84%	A
All Delta Air Lines on LAX–SFO	2,373	65.2%	55 min	1.52%	C
All carriers on LAX–SFO	11,013	64.8%	59 min	0.83%	D+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 1421 quarter by quarter

Quarter by quarter DL 1421 held fairly steady: 95.7% in Jul–Sep 2025, 94.3% in Oct–Dec 2025, 98.7% in Jan–Mar 2026 and 90.7% in Apr–Jun 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights95.7%
Oct–Dec 202589 flights94.3%
Jan–Mar 202683 flights98.7%
Apr–Jun 202688 flights90.7%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, DL 1421 did best on Sunday at 100.0% on time and worst on Friday at 87.5%. Each day rests on about 50 flights, so a gap of 13 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 1421 runs late

One category carries most of the weight here. Carrier accounts for 79% of the 1,180 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
79%
National Airspace System
21%

The largest share of delay minutes, 79%, 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 927 of the 1,180 delay minutes reported here. The split is drawn from 1,180 delay minutes reported on DL 1421.

Cancellations run at 2.84%, against 1.81% nationally. That is roughly one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 2.0% land an hour or more behind schedule, against 8.1% 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.

DL 1421 is not only a LAX to SFO flight. It also flew SFO to LAX (352 flights, 90.6% 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. 352 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 1421
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
SFO to LAXthin sample	352	90.6%	74 min	3.12%	A−

What to do with this

Booking DL 1421

For a booking, the cancellation rate is the figure to plan around on DL 1421: 2.84% of its 352 scheduled flights did not operate. A late arrival costs about an hour, but a cancellation costs the day, so leave a later option open.

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