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Flight Reliability

DL 4109 · Delta Air Lines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and DL 4109 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

68%
Arrive within 15 minutes
33 min
Average arrival delay
2.3%
Cancelled
0 min
Median arrival delay

Based on 344 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon61%(51 flights)
  • Tue78%(51 flights)
  • Wed70%(50 flights)
  • Thu59%(51 flights)
  • Fri71%(49 flights)
  • Sat79%(33 flights)
  • Sun62%(50 flights)
On-time by departure window
  • 6–9 AM97%(30 flights)
  • 3–6 PM—(5 flights)
  • 6–9 PM65%(300 flights)
On-time trend by month
61%
May

Jun 67% → May 61% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202567%27
July 202546%28
August 202589%28
September 202586%29
October 2025100%27
November 202579%24
December 202546%26
January 202655%29
February 202659%27
March 202652%29
April 202677%30
May 202661%31
Departures on time
68%
Diverted
0.3%
Flights flown
335
Months covered
12

Keep nerding

Based on 344 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.