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Flight Reliability

DL 503 · Delta Air Lines

Atlanta → Portland (ATL–PDX)

79
Usually Fine
WanderNerd Reliability Score
74%
Arrive within 15 minutes
11 min
Average arrival delay
0.6%
Cancelled
0 min
Median arrival delay

Based on 352 historical flights. Data through May 2026.

What the data says

Sunday scaries are real for this one.

DL 503 arrived on time 83% of the time on Saturdays and just 61% on Sundays. That gap is worth planning around.

A bit behind the ATL–PDX route.

DL 503 arrived on time 74% of the time, versus 80% across the ATL–PDX route.

Lagging the Delta Air Lines network.

DL 503 arrived on time 74% of the time, versus 81% across the Delta Air Lines network.

Slipping a little lately.

DL 503 arrived on time 75% of the time over the last three months in the data, compared with 80% in the three months before that.

The breakdown

On-time by weekday
  • Mon81%(52 flights)
  • Tue76%(49 flights)
  • Wed78%(50 flights)
  • Thu73%(52 flights)
  • Fri67%(51 flights)
  • Sat83%(47 flights)
  • Sun61%(49 flights)
On-time by departure window
  • 9 AM–12 PM—(2 flights)
  • 3–6 PM74%(348 flights)
On-time trend by month
77%
May

Jun 57% → May 77% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202557%30
July 202565%31
August 202581%31
September 202593%30
October 202567%30
November 202566%29
December 202574%31
January 202683%23
February 202683%24
March 202660%30
April 202687%30
May 202677%31
Departures on time
82%
Diverted
0%
Flights flown
350
Months covered
12

Same route, other flights

Keep nerding

Based on 352 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.