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Flight Reliability

DL 2721 · Delta Air Lines

San Francisco → Seattle (SFO–SEA)97% of its flights flew this route. The rest (BNA–DTW) are included in these numbers.

100
Nerd Approved
WanderNerd Reliability Score
96%
Arrive within 15 minutes
17 min early
Average arrival delay
1.1%
Cancelled
21 min early
Median arrival delay

Based on 358 historical flights. Data through May 2026.

What the data says

Mornings have a slight edge.

Departures between 3–6 AM arrived on time 98% of the time, against 95% between 6–9 AM.

Skip Tuesday if you can.

DL 2721 arrived on time 100% of the time on Wednesdays. On Tuesdays: 92%.

Well ahead of the SFO–SEA route.

DL 2721 arrived on time 96% of the time, versus 75% across the SFO–SEA route.

Better than the Delta Air Lines network average.

DL 2721 arrived on time 96% of the time, versus 81% across the Delta Air Lines network.

The breakdown

On-time by weekday
  • Mon98%(51 flights)
  • Tue92%(52 flights)
  • Wed100%(49 flights)
  • Thu98%(50 flights)
  • Fri96%(52 flights)
  • Sat94%(48 flights)
  • Sun94%(52 flights)
On-time by departure window
  • 3–6 AM98%(207 flights)
  • 6–9 AM95%(139 flights)
  • 3–6 PM—(8 flights)
On-time trend by month
100%
May

Jun 100% → May 100% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 2025100%30
July 202597%31
August 202597%31
September 2025100%30
October 202594%31
November 202593%30
December 202592%25
January 202689%28
February 202693%28
March 2026100%29
April 202697%30
May 2026100%31
Departures on time
96%
Diverted
0%
Flights flown
354
Months covered
12

Same route, other flights

Keep nerding

Based on 358 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.