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Flight Reliability

DL 3631 · Delta Air Lines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and DL 3631 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

84%
Arrive within 15 minutes
2 min
Average arrival delay
0%
Cancelled
8 min early
Median arrival delay

Based on 249 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon89%(36 flights)
  • Tue89%(37 flights)
  • Wed77%(35 flights)
  • Thu86%(35 flights)
  • Fri78%(37 flights)
  • Sat85%(33 flights)
  • Sun83%(36 flights)
On-time by departure window
  • 9 AM–12 PM84%(148 flights)
  • 3–6 PM88%(41 flights)
  • 6–9 PM81%(59 flights)
  • 9 PM–12 AM—(1 flights)
On-time trend by month
91%
Apr

Jun 67% → Apr 91% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202567%21
July 202578%27
August 202584%31
September 202590%30
October 202590%31
November 2025100%12
December 202585%13
January 202688%24
February 202682%22
March 202678%27
April 202691%11
Departures on time
85%
Diverted
0%
Flights flown
249
Months covered
11

Keep nerding

Based on 249 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.