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Flight Reliability

DL 4137 · Delta Air Lines

Spokane → Seattle (GEG–SEA)99% of its flights flew this route. The rest (MSN–DTW, SAN–LAX) are included in these numbers.

100
Nerd Approved
WanderNerd Reliability Score
96%
Arrive within 15 minutes
13 min early
Average arrival delay
0.3%
Cancelled
17 min early
Median arrival delay

Based on 303 historical flights. Data through May 2026.

What the data says

Friday is doing you no favors.

DL 4137 arrived on time 100% of the time on Wednesdays. On Fridays: 91%.

Better than the GEG–SEA route average.

DL 4137 arrived on time 96% of the time, versus 86% across the GEG–SEA route.

Better than the Delta Air Lines network average.

DL 4137 arrived on time 96% of the time, versus 81% across the Delta Air Lines network.

It basically never cancels.

Out of 303 scheduled flights, only 0.3% were cancelled.

The breakdown

On-time by weekday
  • Mon98%(40 flights)
  • Tue98%(42 flights)
  • Wed100%(41 flights)
  • Thu93%(42 flights)
  • Fri91%(43 flights)
  • Sat93%(44 flights)
  • Sun100%(48 flights)
On-time by departure window
  • 6–9 AM96%(299 flights)
  • 3–6 PM—(1 flights)
On-time trend by month
96%
May

Jun 100% → May 96% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 2025100%30
July 202597%31
August 2025100%31
September 2025100%30
October 202587%30
November 2025100%26
December 202597%30
January 202683%29
February 2026100%27
May 202696%26
Departures on time
96%
Diverted
0.7%
Flights flown
300
Months covered
12

Same route, other flights

Keep nerding

Based on 303 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.