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Flight Reliability

DL 903 · Delta Air Lines

Atlanta → Seattle (ATL–SEA)86% of its flights flew this route. The rest (ATL–BWI, ORD–ATL) are included in these numbers.

77
Usually Fine
WanderNerd Reliability Score
79%
Arrive within 15 minutes
5 min
Average arrival delay
2.0%
Cancelled
4 min early
Median arrival delay

Based on 297 historical flights. Data through May 2026.

What the data says

9 PM–12 AM has a slight edge.

Departures between 9 PM–12 AM arrived on time 80% of the time, against 74% between 3–6 PM.

Skip Thursday if you can.

DL 903 arrived on time 86% of the time on Tuesdays. On Thursdays: 72%.

Recent months have been rougher.

DL 903 arrived on time 70% of the time over the last three months in the data, compared with 77% in the three months before that.

The breakdown

On-time by weekday
  • Mon79%(47 flights)
  • Tue86%(35 flights)
  • Wed79%(34 flights)
  • Thu72%(46 flights)
  • Fri80%(46 flights)
  • Sat77%(35 flights)
  • Sun79%(47 flights)
On-time by departure window
  • 12–3 PM—(1 flights)
  • 3–6 PM74%(39 flights)
  • 6–9 PM—(3 flights)
  • 9 PM–12 AM80%(247 flights)
On-time trend by month
58%
May

Jun 79% → May 58% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202579%14
July 202567%15
August 202586%28
September 202597%30
October 202587%31
November 202583%29
December 202573%30
January 202672%29
February 202685%13
March 202667%15
April 202684%25
May 202658%31
Departures on time
79%
Diverted
0.3%
Flights flown
290
Months covered
12

Same route, other flights

Keep nerding

Based on 297 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.