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Flight Reliability

DL 870 · Delta Air Lines

Seattle → Dallas–Fort Worth (SEA–DFW)

64
A Little Dicey
WanderNerd Reliability Score
71%
Arrive within 15 minutes
17 min
Average arrival delay
2.3%
Cancelled
3 min early
Median arrival delay

Based on 349 historical flights. Data through May 2026.

What the data says

Sunday scaries are real for this one.

DL 870 arrived on time 80% of the time on Tuesdays and just 54% on Sundays. That gap is worth planning around.

A bit behind the SEA–DFW route.

DL 870 arrived on time 71% of the time, versus 77% across the SEA–DFW route.

Lagging the Delta Air Lines network.

DL 870 arrived on time 71% of the time, versus 81% across the Delta Air Lines network.

Trending in the right direction.

DL 870 arrived on time 82% of the time over the last three months in the data, compared with 71% in the three months before that.

The breakdown

On-time by weekday
  • Mon66%(50 flights)
  • Tue80%(50 flights)
  • Wed78%(50 flights)
  • Thu72%(50 flights)
  • Fri68%(50 flights)
  • Sat80%(39 flights)
  • Sun54%(50 flights)
On-time by departure window
  • 3–6 PM71%(336 flights)
  • 6–9 PM—(3 flights)
On-time trend by month
86%
May

Jun 50% → May 86% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202550%26
July 202548%27
August 202559%29
September 202577%30
October 202569%29
November 202583%30
December 202567%27
January 202665%26
February 202682%28
March 202686%29
April 202673%30
May 202686%28
Departures on time
72%
Diverted
0.6%
Flights flown
339
Months covered
12

Same route, other flights

Keep nerding

Based on 349 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.