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Flight Reliability

DL 1234 · Delta Air Lines

Atlanta → Miami (ATL–MIA)100% of its flights flew this route. The rest (MIA–ATL) are included in these numbers.

62
A Little Dicey
WanderNerd Reliability Score
63%
Arrive within 15 minutes
22 min
Average arrival delay
0.7%
Cancelled
6 min
Median arrival delay

Based on 290 historical flights. Data through May 2026.

What the data says

The late departure is the smart one here.

DL 1234 departing between 9 PM–12 AM arrived on time 75% of the time, versus 53% between 6–9 PM.

Sunday scaries are real for this one.

DL 1234 arrived on time 79% of the time on Wednesdays and just 49% on Sundays. That gap is worth planning around.

Lagging the ATL–MIA route.

DL 1234 arrived on time 63% of the time, versus 71% across the ATL–MIA route.

Well behind the Delta Air Lines network.

DL 1234 arrived on time 63% of the time, versus 81% across the Delta Air Lines network.

The breakdown

On-time by weekday
  • Mon64%(50 flights)
  • Tue78%(27 flights)
  • Wed79%(28 flights)
  • Thu70%(50 flights)
  • Fri52%(50 flights)
  • Sat62%(34 flights)
  • Sun49%(49 flights)
On-time by departure window
  • 9 AM–12 PM—(1 flights)
  • 12–3 PM—(1 flights)
  • 6–9 PM53%(156 flights)
  • 9 PM–12 AM75%(130 flights)
On-time trend by month
65%
May

Jun 41% → May 65% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202541%17
July 202536%14
August 202565%26
September 202587%30
October 202581%31
November 202570%30
December 202552%29
January 202659%22
February 202667%18
March 202648%29
April 202659%22
May 202665%20
Departures on time
61%
Diverted
0%
Flights flown
288
Months covered
12

Same route, other flights

Keep nerding

Based on 290 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.