Flight number record

DL 1066

Delta Air Lines · San Antonio to Atlanta

Route: SAT → ATL
Departs: 06:30
Flights: 363
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1066, check with Delta Air Lines.

DL 1066 earns an A. Close to nine flights in ten arrive 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 a little over an hour. That rests on 363 flights, with a median arrival 11 minutes early.

Set against the rest of the country, DL 1066's record is 15 points better than the US average of 77.6%. That gap is worth roughly 151 fewer late arrivals for every thousand flights.

On time

92.7%

Arrivals under 15 minutes late, of 356 completed flights

Avg delay

79 min

Across delayed arrivals only, not all flights

Cancelled

1.65%

National rate is 1.81%

1 hour+ late

2.5%

National rate is 8.1%

These figures cover 363 flights between July 2025 and June 2026. The median arrival is 11 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 1066 flies

DL 1066 flies SAT to ATL without a single fixed slot. Its most common scheduled departure was 06:30, used on 103 of 363 flights, with 06:40 (55 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 06:30103 flights28.4%
Departs 06:4055 flights15.2%

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 1066 runs 3 points better at 92.7%. 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 1066 next to SAT to ATL

Every carrier on SAT to ATL combined arrived on time 86.1% of the time across 3,026 flights, so DL 1066 is 7 points ahead of it. Delta flew 2,609 flights on the same city pair under all its flight numbers, including this one, and those ran 87.8% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 11 points.

DL 1066 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1066thin sample	363	92.7%	79 min	1.65%	A
All Delta Air Lines on SAT–ATL	2,609	87.8%	75 min	1.76%	A
All carriers on SAT–ATL	3,026	86.1%	72 min	1.55%	A
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 1066 quarter by quarter

Quarter by quarter DL 1066 held fairly steady: 94.3% in Jul–Sep 2025, 92.2% in Oct–Dec 2025, 94.4% in Jan–Mar 2026 and 90.0% in Apr–Jun 2026. A spread of 4 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202590 flights94.3%
Oct–Dec 202592 flights92.2%
Jan–Mar 202690 flights94.4%
Apr–Jun 202691 flights90.0%

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

By weekday, DL 1066 did best on Wednesday at 98.1% on time and worst on Saturday at 83.7%. Each day rests on about 52 flights, so a gap of 14 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 1066 runs late

One category carries most of the weight here. Carrier accounts for 62% of the 2,046 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
62%
Extreme weather
25%
National Airspace System
13%

Extreme weather accounts for 25% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.9 times the usual weather exposure. The split is drawn from 2,046 delay minutes reported on DL 1066.

Cancellations sit at 1.65% against a national 1.81%, which is ordinary. Diversions add another 0.28%.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 2.5% 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.

The 874 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

Every one of the 363 flights under DL 1066 in the data flew SAT 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. 363 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 1066

For a booking, read DL 1066 as 92.7% on time with 1.65% cancelled over 363 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