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Flight Reliability

DL 4037 · Delta Air Lines

SUN → Salt Lake City (SUN–SLC)

100
Nerd Approved
WanderNerd Reliability Score
98%
Arrive within 15 minutes
14 min early
Average arrival delay
0.8%
Cancelled
19 min early
Median arrival delay

Based on 363 historical flights. Data through May 2026.

What the data says

Saturday has been the better bet.

A small edge: 100% on time on Saturdays against 96% on Thursdays.

A bit ahead of the SUN–SLC route.

DL 4037 arrived on time 98% of the time, versus 95% across the SUN–SLC route.

Well ahead of the Delta Air Lines network.

DL 4037 arrived on time 98% of the time, versus 81% across the Delta Air Lines network.

The breakdown

On-time by weekday
  • Mon98%(51 flights)
  • Tue98%(51 flights)
  • Wed98%(50 flights)
  • Thu96%(51 flights)
  • Fri98%(52 flights)
  • Sat100%(52 flights)
  • Sun100%(53 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 2025100%31
August 2025100%31
September 2025100%30
October 2025100%31
November 2025100%30
December 202593%30
January 202697%29
February 202696%28
March 2026100%31
April 202693%30
May 2026100%29
Departures on time
98%
Diverted
0%
Flights flown
360
Months covered
12

Same route, other flights

Keep nerding

Based on 363 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.