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Flight Reliability

DL 5621 · Delta Air Lines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and DL 5621 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

77%
Arrive within 15 minutes
18 min
Average arrival delay
2.7%
Cancelled
10 min early
Median arrival delay

Based on 296 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon87%(39 flights)
  • Tue79%(42 flights)
  • Wed74%(42 flights)
  • Thu68%(44 flights)
  • Fri79%(43 flights)
  • Sat78%(36 flights)
  • Sun77%(31 flights)
On-time by departure window
  • 6–9 AM—(3 flights)
  • 9 AM–12 PM90%(70 flights)
  • 12–3 PM75%(67 flights)
  • 3–6 PM72%(137 flights)
On-time trend by month
100%
May

Jun 59% → May 100% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202559%27
July 202546%22
August 202579%29
September 202586%28
October 202577%26
December 202592%12
January 2026100%10
February 2026100%11
March 202668%40
April 202682%54
May 2026100%17
Departures on time
77%
Diverted
3.7%
Flights flown
277
Months covered
12

Keep nerding

Based on 296 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.