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Flight Reliability

DL 1257 · Delta Air Lines

Atlanta → Baltimore (ATL–BWI)93% of its flights flew this route. The rest (LAS–SEA) are included in these numbers.

65
Usually Fine
WanderNerd Reliability Score
70%
Arrive within 15 minutes
20 min
Average arrival delay
1.5%
Cancelled
1 min
Median arrival delay

Based on 327 historical flights. Data through May 2026.

What the data says

The 12–3 PM departure wins.

DL 1257 departing between 12–3 PM arrived on time 92% of the time, versus 68% between 6–9 PM.

Saturday is the weak spot.

DL 1257 arrived on time 72% of the time on Wednesdays. On Saturdays: 65%.

A bit behind the ATL–BWI route.

DL 1257 arrived on time 70% of the time, versus 75% across the ATL–BWI route.

Lagging the Delta Air Lines network.

DL 1257 arrived on time 70% of the time, versus 81% across the Delta Air Lines network.

The breakdown

On-time by weekday
  • Mon71%(49 flights)
  • Tue71%(45 flights)
  • Wed72%(43 flights)
  • Thu69%(45 flights)
  • Fri67%(46 flights)
  • Sat65%(43 flights)
  • Sun70%(50 flights)
On-time by departure window
  • 12–3 PM92%(24 flights)
  • 6–9 PM68%(296 flights)
  • 9 PM–12 AM—(1 flights)
On-time trend by month
62%
May

Jun 35% → May 62% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202535%29
July 202548%29
August 202571%31
September 202577%30
October 202586%21
November 202582%27
December 202582%28
January 202653%15
February 202689%26
March 202657%30
April 202696%26
May 202662%29
Departures on time
73%
Diverted
0.3%
Flights flown
321
Months covered
12

Same route, other flights

Keep nerding

Based on 327 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.