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Flight Reliability

DL 1251 · Delta Air Lines

Atlanta → Tucson (ATL–TUS)91% of its flights flew this route. The rest (ATL–GSP, GSP–ATL) are included in these numbers.

77
Usually Fine
WanderNerd Reliability Score
77%
Arrive within 15 minutes
5 min
Average arrival delay
2.2%
Cancelled
4 min early
Median arrival delay

Based on 360 historical flights. Data through May 2026.

What the data says

Morning flights do better here.

DL 1251 departing between 9 AM–12 PM arrived on time 100% of the time, versus 68% between 9 PM–12 AM.

Thursdays have been rough.

DL 1251 arrived on time 89% of the time on Saturdays and just 73% on Thursdays. That gap is worth planning around.

A bit behind the ATL–TUS route.

DL 1251 arrived on time 77% of the time, versus 83% across the ATL–TUS route.

A bit behind the Delta Air Lines network.

DL 1251 arrived on time 77% of the time, versus 81% across the Delta Air Lines network.

The breakdown

On-time by weekday
  • Mon76%(54 flights)
  • Tue75%(48 flights)
  • Wed81%(48 flights)
  • Thu73%(51 flights)
  • Fri77%(51 flights)
  • Sat89%(45 flights)
  • Sun73%(55 flights)
On-time by departure window
  • 9 AM–12 PM100%(15 flights)
  • 12–3 PM94%(18 flights)
  • 3–6 PM—(7 flights)
  • 6–9 PM81%(181 flights)
  • 9 PM–12 AM68%(131 flights)
On-time trend by month
81%
May

Jun 62% → May 81% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202562%29
July 202563%30
August 202573%30
September 202587%30
October 202571%31
November 202583%29
December 202581%41
January 202678%23
February 202670%20
March 202682%28
April 202693%30
May 202681%31
Departures on time
79%
Diverted
0%
Flights flown
352
Months covered
12

Same route, other flights

Keep nerding

Based on 360 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.