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Flight Reliability

DL 3634 · Delta Air Lines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and DL 3634 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

91%
Arrive within 15 minutes
8 min early
Average arrival delay
0.5%
Cancelled
15 min early
Median arrival delay

Based on 392 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon86%(57 flights)
  • Tue88%(57 flights)
  • Wed94%(54 flights)
  • Thu98%(53 flights)
  • Fri86%(58 flights)
  • Sat96%(51 flights)
  • Sun92%(59 flights)
On-time by departure window
  • 9 AM–12 PM78%(23 flights)
  • 3–6 PM93%(270 flights)
  • 6–9 PM90%(96 flights)
On-time trend by month
81%
Feb

Jun 94% → Feb 81% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202594%46
July 202595%37
August 202586%49
September 2025100%59
October 202592%62
November 202595%58
December 202586%51
February 202681%16
Departures on time
91%
Diverted
0.3%
Flights flown
389
Months covered
10

Keep nerding

Based on 392 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.