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Flight Reliability

DL 3940 · Delta Air Lines

Colorado Springs → Salt Lake City (COS–SLC)

100
Nerd Approved
WanderNerd Reliability Score
96%
Arrive within 15 minutes
10 min early
Average arrival delay
0%
Cancelled
14 min early
Median arrival delay

Based on 365 historical flights. Data through May 2026.

What the data says

Sunday scaries are real for this one.

DL 3940 arrived on time 98% of the time on Mondays. On Sundays: 91%.

A bit ahead of the COS–SLC route.

DL 3940 arrived on time 96% of the time, versus 93% across the COS–SLC route.

Better than the Delta Air Lines network average.

DL 3940 arrived on time 96% of the time, versus 81% across the Delta Air Lines network.

It basically never cancels.

Out of 365 scheduled flights, only 0.0% were cancelled.

The breakdown

On-time by weekday
  • Mon98%(52 flights)
  • Tue98%(52 flights)
  • Wed96%(52 flights)
  • Thu96%(52 flights)
  • Fri96%(52 flights)
  • Sat98%(52 flights)
  • Sun91%(53 flights)
On-time trend by month
100%
May

Jun 97% → May 100% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202597%30
July 202594%31
August 202597%31
September 202597%30
October 2025100%31
November 2025100%30
December 202594%31
January 202690%31
February 202696%28
March 202697%31
April 202693%30
May 2026100%31
Departures on time
96%
Diverted
0%
Flights flown
365
Months covered
12

Same route, other flights

Keep nerding

Based on 365 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.