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Flight Reliability

DL 3121 · Delta Air Lines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and DL 3121 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

81%
Arrive within 15 minutes
5 min
Average arrival delay
3.9%
Cancelled
8 min early
Median arrival delay

Based on 279 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon84%(43 flights)
  • Tue83%(42 flights)
  • Wed88%(41 flights)
  • Thu81%(41 flights)
  • Fri72%(39 flights)
  • Sat83%(23 flights)
  • Sun80%(39 flights)
On-time by departure window
  • 12–3 PM79%(110 flights)
  • 9 PM–12 AM83%(158 flights)
On-time trend by month
71%
May

Oct 95% → May 71% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
October 202595%38
November 202579%38
December 202566%44
January 202686%28
February 202678%27
March 202683%29
April 2026100%30
May 202671%28
Departures on time
80%
Diverted
0%
Flights flown
268
Months covered
10

Keep nerding

Based on 279 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.