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Flight Reliability

AS 657 · Alaska Airlines

Seattle → San Jose (SEA–SJC)100% of its flights flew this route. The rest (RDU–SEA) are included in these numbers.

86
Pretty Reliable
WanderNerd Reliability Score
78%
Arrive within 15 minutes
3 min
Average arrival delay
0%
Cancelled
5 min early
Median arrival delay

Based on 210 historical flights. Data through May 2026.

What the data says

The 6–9 AM departure wins.

AS 657 departing between 6–9 AM arrived on time 86% of the time, versus 76% between 9 AM–12 PM.

Friday is doing you no favors.

AS 657 arrived on time 91% of the time on Sundays and just 61% on Fridays. That gap is worth planning around.

A bit behind the SEA–SJC route.

AS 657 arrived on time 78% of the time, versus 82% across the SEA–SJC route.

It basically never cancels.

Out of 210 scheduled flights, only 0.0% were cancelled.

The breakdown

On-time by weekday
  • Mon68%(31 flights)
  • Tue79%(28 flights)
  • Wed75%(28 flights)
  • Thu84%(31 flights)
  • Fri61%(31 flights)
  • Sat86%(29 flights)
  • Sun91%(32 flights)
On-time by departure window
  • 6–9 AM86%(35 flights)
  • 9 AM–12 PM76%(175 flights)
On-time trend by month
84%
May

Nov 67% → May 84% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
November 202567%27
December 202564%25
January 202677%31
February 202671%28
March 202690%31
April 202683%30
May 202684%31
Departures on time
77%
Diverted
0%
Flights flown
210
Months covered
8

Same route, other flights

Keep nerding

Based on 210 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.