Flight number record

DL 903

Delta Air Lines · Atlanta to Seattle

Route: ATL → SEA
Departs: 21:20
Flights: 268
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 903, check with Delta Air Lines.

DL 903 lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 55 minutes on average. That is a workable record, not a spotless one. That rests on 268 flights, with a median arrival 5 minutes early.

On time

78.9%

Arrivals under 15 minutes late, of 266 completed flights

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

0.75%

National rate is 1.81%

1 hour+ late

5.3%

National rate is 8.1%

These figures cover 268 flights between July 2025 and June 2026. The median arrival is 5 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 903 flies

DL 903 flies ATL to SEA without a single fixed slot. Its most common scheduled departure was 21:20, used on 77 of 268 flights, with 21:25 (76 flights) and 21:34 (31 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 21:2077 flights28.7%
Departs 21:2576 flights28.4%
Departs 21:3431 flights11.6%

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 21:20 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and DL 903 runs 8 points better at 78.9%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

DL 903 next to ATL to SEA

Every carrier on ATL to SEA combined arrived on time 77.8% of the time across 3,277 flights, so DL 903 is about level with it. Delta flew 2,371 flights on the same city pair under all its flight numbers, including this one, and those ran 79.1% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 3 points.

DL 903 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 903thin sample	268	78.9%	54 min	0.75%	B+
All Delta Air Lines on ATL–SEA	2,371	79.1%	53 min	0.46%	B+
All carriers on ATL–SEA	3,277	77.8%	54 min	0.64%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 903 quarter by quarter

DL 903 did not run the same all year. Its best quarter was Jul–Sep 2025 at 86.1% on time and its weakest Apr–Jun 2026 at 73.3%, a swing of 13 points on roughly 89 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 202572 flights86.1%
Oct–Dec 202592 flights80.0%
Jan–Mar 202618 flights—
Apr–Jun 202686 flights73.3%

Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, DL 903 ranged from 73.8% on Thursday to 84.8% on Tuesday. With about 38 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 903 runs late

One category carries most of the weight here. Carrier accounts for 70% of the 3,041 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
70%
Late-arriving aircraft
13%
National Airspace System
12%
Extreme weather
5%

The largest share of delay minutes, 70%, 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 2,137 of the 3,041 delay minutes reported here. The split is drawn from 3,041 delay minutes reported on DL 903.

Cancellations are rare at 0.75%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

5.3% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 55 minutes, which a normal layover absorbs.

At 2,182 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 two other city pairs in the data, including ATL to BWI (42) and ORD to ATL (1), but none flew often enough under DL 903 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ATL to SEA only.

One caution: this is a thin sample. 268 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 903

For a booking, read DL 903 as 78.9% on time with 0.75% cancelled over 268 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