Skip to content
WanderNerd
Check a flight

Flight Reliability

DL 4131 · Delta Air Lines

Seattle → Sacramento (SEA–SMF)100% of its flights flew this route. The rest (DTW–IND) are included in these numbers.

97
Nerd Approved
WanderNerd Reliability Score
90%
Arrive within 15 minutes
7 min early
Average arrival delay
0.3%
Cancelled
13 min early
Median arrival delay

Based on 320 historical flights. Data through May 2026.

What the data says

6–9 PM has a slight edge.

Departures between 6–9 PM arrived on time 91% of the time, against 87% between 9 PM–12 AM.

Thursdays have been rough.

DL 4131 arrived on time 98% of the time on Wednesdays and just 81% on Thursdays. That gap is worth planning around.

Better than the SEA–SMF route average.

DL 4131 arrived on time 90% of the time, versus 82% across the SEA–SMF route.

Better than the Delta Air Lines network average.

DL 4131 arrived on time 90% of the time, versus 81% across the Delta Air Lines network.

The breakdown

On-time by weekday
  • Mon92%(47 flights)
  • Tue94%(47 flights)
  • Wed98%(47 flights)
  • Thu81%(47 flights)
  • Fri89%(46 flights)
  • Sat95%(37 flights)
  • Sun85%(48 flights)
On-time by departure window
  • 3–6 PM—(5 flights)
  • 6–9 PM91%(276 flights)
  • 9 PM–12 AM87%(38 flights)
On-time trend by month
90%
May

Jun 83% → May 90% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202583%30
July 202587%31
August 202591%22
September 2025100%17
October 202587%30
November 202593%28
December 202584%19
January 202696%28
February 202696%24
March 202693%29
April 202687%30
May 202690%31
Departures on time
90%
Diverted
0%
Flights flown
319
Months covered
12

Same route, other flights

Keep nerding

Based on 320 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.