Flight number record

DL 816

Delta Air Lines · San Antonio to Boston

Route: SAT → BOS
Departs: 14:40
Flights: 313
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 816, check with Delta Air Lines.

DL 816 draws a D. Roughly one flight in two arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 313 flights, with a median arrival 7 minutes late.

The national on-time rate over the same period is 77.6%, so DL 816 runs 18 points behind the country as a whole. Across a thousand flights that is about 181 extra late arrivals.

On time

59.5%

Arrivals under 15 minutes late, of 304 completed flights

Avg delay

82 min

Across delayed arrivals only, not all flights

Cancelled

1.92%

National rate is 1.81%

1 hour+ late

20.4%

National rate is 8.1%

These figures cover 313 flights between July 2025 and June 2026. Beyond the headline rate, 20.4% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Schedule

When DL 816 flies

DL 816 flies SAT to BOS without a single fixed slot. Its most common scheduled departure was 14:40, used on 64 of 313 flights, with 12:22 (36 flights) and 12:25 (33 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 14:4064 flights20.4%
Departs 12:2236 flights11.5%
Departs 12:2533 flights10.5%

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 14:40 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and DL 816 runs 13 points worse at 59.5%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 816 next to SAT to BOS

Every carrier on SAT to BOS combined arrived on time 60.9% of the time across 355 flights, so DL 816 is about level with it. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 22 points.

DL 816 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 816thin sample	313	59.5%	82 min	1.92%	D
All Delta Air Lines on SAT–BOSthin sample	355	60.9%	80 min	2.25%	D
All carriers on SAT–BOSthin sample	355	60.9%	80 min	2.25%	D
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 816 quarter by quarter

DL 816 did not run the same all year. Its best quarter was Jan–Mar 2026 at 71.1% on time and its weakest Jul–Sep 2025 at 48.9%, a swing of 22 points on roughly 78 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 202590 flights48.9%
Oct–Dec 202577 flights55.3%
Jan–Mar 202686 flights71.1%
Apr–Jun 202660 flights64.9%

Scale runs 40% to 75%. Rows with fewer than 30 flights show a dash.

By weekday, DL 816 did best on Saturday at 72.7% on time and worst on Friday at 46.3%. Each day rests on about 45 flights, so a gap of 26 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 816 runs late

One category carries most of the weight here. National Airspace System accounts for 47% of the 10,000 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.

National Airspace System
47%
Late-arriving aircraft
33%
Carrier
17%
Extreme weather
3%

47% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 4,694 minutes out of 10,000, against a national NAS share of 21%. The split is drawn from 10,088 delay minutes reported on DL 816.

Cancellations sit at 1.92% against a national 1.81%, which is ordinary. Diversions add another 0.96%.

Connections and routes

What a delay on this flight costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 20.4% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

At 1,764 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 three other city pairs in the data, including MCO to LAX (31), BOS to SAT (24) and JAC to SLC (16), but none flew often enough under DL 816 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SAT to BOS only.

One caution: this is a thin sample. 313 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 816

For a booking, DL 816 is a flight to put a long connection behind. 20.4% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.

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