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Airline Reliability

Delta Air Lines

Carrier code DL · 1,650,384 flights in the data

81
Pretty Reliable
WanderNerd Reliability Score
81%
Arrive within 15 minutes
5 min
Average arrival delay
2.0%
Cancelled
8 min early
Median arrival delay

Data through May 2026.

What the data says

Morning-you made the right choice.

Delta Air Lines flights departing between 3–6 AM arrived on time 92% of the time, versus 73% between 6–9 PM.

Wednesday has been the better bet.

A small edge: 84% on time on Wednesdays against 78% on Sundays.

Ticking up lately.

Delta Air Lines flights arrived on time 82% of the time over the last three months in the data, compared with 79% in the three months before that.

The breakdown

On-time by weekday
  • Mon80%(237719 flights)
  • Tue83%(232290 flights)
  • Wed84%(231712 flights)
  • Thu82%(237339 flights)
  • Fri81%(237665 flights)
  • Sat83%(200068 flights)
  • Sun78%(236971 flights)
On-time by departure window
  • 12–3 AM86%(2566 flights)
  • 3–6 AM92%(38276 flights)
  • 6–9 AM89%(337957 flights)
  • 9 AM–12 PM85%(303610 flights)
  • 12–3 PM81%(285968 flights)
  • 3–6 PM76%(300752 flights)
  • 6–9 PM73%(231670 flights)
  • 9 PM–12 AM78%(112965 flights)
On-time trend by month
83%
May

Jun 76% → May 83% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202576%139445
July 202577%143628
August 202584%141929
September 202588%134415
October 202585%141352
November 202583%128566
December 202574%130338
January 202680%121193
February 202683%115786
March 202679%134685
April 202685%138157
May 202683%144270

Busiest Delta Air Lines routes

Biggest airports

Based on 1,650,384 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.