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Flight Reliability

DL 1399 · Delta Air Lines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and DL 1399 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

80%
Arrive within 15 minutes
9 min
Average arrival delay
1.5%
Cancelled
6 min early
Median arrival delay

Based on 581 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon81%(82 flights)
  • Tue85%(82 flights)
  • Wed85%(81 flights)
  • Thu77%(82 flights)
  • Fri79%(85 flights)
  • Sat75%(75 flights)
  • Sun76%(84 flights)
On-time by departure window
  • 6–9 AM85%(338 flights)
  • 9 AM–12 PM77%(190 flights)
  • 12–3 PM47%(34 flights)
  • 3–6 PM—(9 flights)
On-time trend by month
80%
May

Jun 75% → May 80% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202575%60
July 202583%59
August 202594%62
September 202581%59
October 202565%62
November 202581%58
December 202576%45
January 202674%27
February 202678%23
March 202687%30
April 202683%30
May 202680%56
Departures on time
83%
Diverted
0.2%
Flights flown
571
Months covered
12

Keep nerding

Based on 581 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.