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Flight Reliability

DL 1223 · Delta Air Lines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and DL 1223 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

80%
Arrive within 15 minutes
7 min
Average arrival delay
2.2%
Cancelled
7 min early
Median arrival delay

Based on 460 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon78%(64 flights)
  • Tue79%(68 flights)
  • Wed78%(68 flights)
  • Thu79%(66 flights)
  • Fri80%(66 flights)
  • Sat82%(54 flights)
  • Sun81%(64 flights)
On-time by departure window
  • 9 AM–12 PM81%(179 flights)
  • 12–3 PM82%(49 flights)
  • 3–6 PM78%(99 flights)
  • 6–9 PM77%(87 flights)
  • 9 PM–12 AM81%(36 flights)
On-time trend by month
73%
May

Jun 89% → May 73% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202589%37
July 202587%31
August 202594%31
September 202570%30
October 202568%31
November 202587%30
December 202578%40
January 202666%50
February 202681%53
March 202678%36
April 202688%48
May 202673%33
Departures on time
77%
Diverted
0%
Flights flown
450
Months covered
12

Keep nerding

Based on 460 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.