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WanderNerd

Flight Reliability

DL 661 · Delta Air Lines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and DL 661 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

73%
Arrive within 15 minutes
14 min
Average arrival delay
2.5%
Cancelled
3 min early
Median arrival delay

Based on 684 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon73%(93 flights)
  • Tue76%(97 flights)
  • Wed87%(97 flights)
  • Thu84%(97 flights)
  • Fri68%(98 flights)
  • Sat71%(93 flights)
  • Sun54%(91 flights)
On-time by departure window
  • 6–9 AM88%(60 flights)
  • 9 AM–12 PM85%(59 flights)
  • 12–3 PM75%(79 flights)
  • 3–6 PM70%(253 flights)
  • 6–9 PM70%(215 flights)
On-time trend by month
78%
May

Jun 55% → May 78% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202555%53
July 202549%57
August 202563%62
September 202578%60
October 202587%62
November 202586%59
December 202573%48
January 202690%52
February 202680%56
March 202663%60
April 202678%60
May 202678%37
Departures on time
76%
Diverted
0.1%
Flights flown
666
Months covered
12

Based on 684 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.