Flight number record

DL 503

Delta Air Lines · Atlanta to Portland

Route: ATL → PDX
Departs: 16:59
Flights: 352
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 503, check with Delta Air Lines.

DL 503 sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land roughly 55 minutes behind schedule. That rests on 352 flights, with a median arrival right on schedule.

On time

74.3%

Arrivals under 15 minutes late, of 350 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

0.57%

National rate is 1.81%

1 hour+ late

5.7%

National rate is 8.1%

These figures cover 352 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Schedule

When DL 503 flies

DL 503 flies ATL to PDX without a single fixed slot. Its most common scheduled departure was 16:59, used on 97 of 352 flights, with 17:15 (39 flights) and 16:48 (36 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 16:5997 flights27.6%
Departs 17:1539 flights11.1%
Departs 16:4836 flights10.2%

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 16:59 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and DL 503 runs level with that at 74.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 503 next to ATL to PDX

Every carrier on ATL to PDX combined arrived on time 79.6% of the time across 1,576 flights, so DL 503 is 5 points behind it. Delta flew 1,288 flights on the same city pair under all its flight numbers, including this one, and those ran 79.0% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 7 points.

DL 503 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 503thin sample	352	74.3%	53 min	0.57%	C+
All Delta Air Lines on ATL–PDX	1,288	79.0%	49 min	1.01%	B
All carriers on ATL–PDX	1,576	79.6%	53 min	0.89%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 503 quarter by quarter

DL 503 did not run the same all year. Its best quarter was Jul–Sep 2025 at 79.3% on time and its weakest Oct–Dec 2025 at 66.7%, a swing of 13 points on roughly 88 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 flights79.3%
Oct–Dec 202590 flights66.7%
Jan–Mar 202679 flights72.7%
Apr–Jun 202691 flights78.0%

Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, DL 503 did best on Saturday at 85.1% on time and worst on Sunday at 62.5%. Each day rests on about 50 flights, so a gap of 23 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 503 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 4,801 reported delay minutes.

Carrier
40%
National Airspace System
33%
Extreme weather
15%
Late-arriving aircraft
12%

Extreme weather accounts for 15% 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 2.4 times the usual weather exposure. The split is drawn from 4,801 delay minutes reported on DL 503.

Cancellations are rare at 0.57%, 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

5.7% 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 roughly 55 minutes, which a normal layover absorbs.

At 2,172 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 352 flights under DL 503 in the data flew ATL to PDX. 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. 352 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 503

For a booking, DL 503 is one of the weaker ways to fly ATL to PDX: 5 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.

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