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WanderNerd

Flight Reliability

DL 1603 · Delta Air Lines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and DL 1603 moved between routes during this period. Numbers below combine all of them, so treat them as background, not a verdict. For a cleaner answer, check the route you are actually flying.

Combined across all its routes

83%
Arrive within 15 minutes
2 min
Average arrival delay
0.9%
Cancelled
8 min early
Median arrival delay

Based on 217 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon85%(27 flights)
  • Tue79%(33 flights)
  • Wed83%(29 flights)
  • Thu74%(27 flights)
  • Fri81%(32 flights)
  • Sat91%(34 flights)
  • Sun88%(33 flights)
On-time by departure window
  • 6–9 AM84%(57 flights)
  • 9 AM–12 PM(2 flights)
  • 12–3 PM90%(61 flights)
  • 3–6 PM74%(35 flights)
  • 6–9 PM82%(56 flights)
  • 9 PM–12 AM(4 flights)
On-time trend by month
70%
Apr

Jun 83% → Apr 70% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202583%47
July 202587%52
August 2025100%20
December 202583%12
January 202671%17
February 202676%21
April 202670%20
Departures on time
89%
Diverted
0%
Flights flown
215
Months covered
11

Based on 217 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.