Flight number record

DL 729

Delta Air Lines · San Diego to Atlanta

Route: SAN → ATL
Departs: 06:15
Flights: 365
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 729, check with Delta Air Lines.

DL 729 earns an A. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 15 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 365 flights, with a median arrival 6 minutes early.

Set against the rest of the country, DL 729's record is 15 points better than the US average of 77.6%. That gap is worth roughly 154 fewer late arrivals for every thousand flights.

On time

93.0%

Arrivals under 15 minutes late, of 358 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

1.10%

National rate is 1.81%

1 hour+ late

0.8%

National rate is 8.1%

These figures cover 365 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 729 flies

DL 729 flies SAN to ATL without a single fixed slot. Its most common scheduled departure was 06:15, used on 253 of 365 flights, with 06:30 (62 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 06:15253 flights69.3%
Departs 06:3062 flights17.0%

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 06:15 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 729 runs 4 points better at 93.0%. 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 729 next to SAN to ATL

Every carrier on SAN to ATL combined arrived on time 85.5% of the time across 2,412 flights, so DL 729 is 8 points ahead of it. Delta flew 2,171 flights on the same city pair under all its flight numbers, including this one, and those ran 86.9% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 11 points.

DL 729 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 729	365	93.0%	53 min	1.10%	A
All Delta Air Lines on SAN–ATL	2,171	86.9%	69 min	0.74%	A+
All carriers on SAN–ATL	2,412	85.5%	66 min	0.70%	A+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 729 quarter by quarter

DL 729 did not run the same all year. Its best quarter was Oct–Dec 2025 at 97.8% on time and its weakest Jan–Mar 2026 at 85.2%, a swing of 13 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.

Jul–Sep 202592 flights96.6%
Oct–Dec 202592 flights97.8%
Jan–Mar 202690 flights85.2%
Apr–Jun 202691 flights92.2%

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, DL 729 ranged from 88.5% on Thursday to 98.0% on Sunday. With about 52 flights behind each day, a spread of 10 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 729 runs late

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 1,322 reported delay minutes.

Late-arriving aircraft
40%
Carrier
30%
National Airspace System
29%
Extreme weather
1%

40% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 1,322 reported delay minutes here, that single category outweighs weather by 31 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 1,322 delay minutes reported on DL 729.

Cancellations sit at 1.10% against a national 1.81%, which is ordinary. Diversions add another 0.82%.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 0.8% 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.

At 1,892 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.

Every one of the 365 flights under DL 729 in the data flew SAN to ATL. The number was not reused on any other city pair, which makes this a clean record of one route.

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 729

For a booking, DL 729 has one of the better records a US domestic flight can show: 93.0% on time and 1.10% cancelled. That is a base rate, not a promise about any single 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