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Flight Reliability

DL 519 · Delta Air Lines

Atlanta → Denver (ATL–DEN)97% of its flights flew this route. The rest (DEN–ATL) are included in these numbers.

56
A Little Dicey
WanderNerd Reliability Score
61%
Arrive within 15 minutes
19 min
Average arrival delay
0.8%
Cancelled
7 min
Median arrival delay

Based on 377 historical flights. Data through May 2026.

What the data says

The late departure is the smart one here.

DL 519 departing between 6–9 PM arrived on time 76% of the time, versus 59% between 3–6 PM.

Sunday scaries are real for this one.

DL 519 arrived on time 69% of the time on Wednesdays and just 54% on Sundays. That gap is worth planning around.

Well behind the ATL–DEN route.

DL 519 arrived on time 61% of the time, versus 77% across the ATL–DEN route.

Well behind the Delta Air Lines network.

DL 519 arrived on time 61% of the time, versus 81% across the Delta Air Lines network.

The breakdown

On-time by weekday
  • Mon57%(53 flights)
  • Tue61%(51 flights)
  • Wed69%(52 flights)
  • Thu65%(52 flights)
  • Fri67%(54 flights)
  • Sat55%(53 flights)
  • Sun54%(54 flights)
On-time by departure window
  • 3–6 PM59%(320 flights)
  • 6–9 PM76%(49 flights)
On-time trend by month
65%
May

Jun 14% → May 65% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202514%29
July 202528%29
August 202553%30
September 202577%30
October 202573%30
November 202570%30
December 202545%40
January 202682%33
February 202679%28
March 202676%29
April 202673%30
May 202665%31
Departures on time
68%
Diverted
1.3%
Flights flown
369
Months covered
12

Same route, other flights

Keep nerding

Based on 377 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.