Flight number record

DL 812

Delta Air Lines · Seattle to Detroit

Route: SEA → DTW
Departs: 06:00
Flights: 365
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 812, check with Delta Air Lines.

DL 812 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 13 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 365 flights, with a median arrival 13 minutes early.

Set against the rest of the country, DL 812's record is 13 points better than the US average of 77.6%. That gap is worth roughly 129 fewer late arrivals for every thousand flights.

On time

90.5%

Arrivals under 15 minutes late, of 359 completed flights

Avg delay

94 min

Across delayed arrivals only, not all flights

Cancelled

1.10%

National rate is 1.81%

1 hour+ late

3.9%

National rate is 8.1%

These figures cover 365 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 812 flies

DL 812 flies SEA to DTW without a single fixed slot. Its most common scheduled departure was 06:00, used on 236 of 365 flights, with 05:30 (55 flights) and 06:05 (38 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 06:00236 flights64.7%
Departs 05:3055 flights15.1%
Departs 06:0538 flights10.4%

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 06:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 812 runs level with that at 90.5%. 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 812 next to SEA to DTW

Every carrier on SEA to DTW combined arrived on time 84.7% of the time across 2,072 flights, so DL 812 is 6 points ahead of it. Delta flew 1,532 flights on the same city pair under all its flight numbers, including this one, and those ran 85.3% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 9 points.

DL 812 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 812	365	90.5%	94 min	1.10%	A
All Delta Air Lines on SEA–DTW	1,532	85.3%	65 min	1.04%	A
All carriers on SEA–DTW	2,072	84.7%	59 min	0.82%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 812 quarter by quarter

Quarter by quarter DL 812 held fairly steady: 84.3% in Jul–Sep 2025, 93.5% in Oct–Dec 2025, 93.3% in Jan–Mar 2026 and 91.0% in Apr–Jun 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights84.3%
Oct–Dec 202592 flights93.5%
Jan–Mar 202690 flights93.3%
Apr–Jun 202691 flights91.0%

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

By weekday, DL 812 ranged from 86.5% on Friday to 94.2% on Monday. With about 52 flights behind each day, a spread of 8 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 812 runs late

One category carries most of the weight here. Carrier accounts for 48% of the 3,185 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
48%
Late-arriving aircraft
31%
National Airspace System
11%
Extreme weather
9%

The largest share of delay minutes, 48%, 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 1,529 of the 3,185 delay minutes reported here. The split is drawn from 3,185 delay minutes reported on DL 812.

Cancellations sit at 1.10% against a national 1.81%, which is ordinary. Diversions add another 0.55%.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 3.9% 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 1,927 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 812 in the data flew SEA to DTW. 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 812

For a booking, DL 812 has one of the better records a US domestic flight can show: 90.5% 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