ON TIMEBOARD

AS 528 on time

Alaska Airlines 528: Seattle to San Francisco at 8:53 a.m. (past 12 months)

On time
50%
250 flights · likely 43–56%
Cancelled
1.2%
of scheduled flights
Typical arrival
+14 min
median vs schedule
When late
+52 min
average delay
Similar flights
53%
AS, same route & hour

About 5 in 10 AS 528 flights from Seattle arrived 15+ minutes late, diverted or cancelled over the past year (50%); 1.2% were cancelled. The typical flight landed 14 minutes late.

AS 528: SEA → SFO

Scheduled to leave Seattle at 8:53 a.m. local time. Over the past year it arrived on time 50% of the time (250 flights), worse than other AS flights on the route at that hour (53%). Last seen in the data Aug 31, 2026.

Month by month

20%60%100%Oct 2025: too few flights (6 flights)OctNov 2025: 61% on time (23 flights)61NovDec 2025: 65% on time (26 flights)65DecJan 2026: 83% on time (29 flights)83JanFeb 2026: 68% on time (22 flights)68FebMar 2026: too few flights (14 flights)MarApr 2026: too few flights (12 flights)AprMay 2026: 29% on time (28 flights)29MayJun 2026: 36% on time (28 flights)36JunJul 2026: 35% on time (31 flights)35JulAug 2026: 32% on time (31 flights)32Aug

By day of week

DayFlightsOn time
Monday3949%
Tuesday3447%
Wednesday3653%
Thursday3644%
Friday3861%
Saturday2752%
Sunday4043%

Why it was late

Air traffic & airport (NAS) 71%Late inbound plane 15%Airline (crew, maintenance, ops) 12%Severe weather 1%

All flights SEA → SFO · Connecting off AS 528? Check the risk

Questions

How often is AS 528 from SEA to SFO late?

Alaska Airlines 528 from Seattle, WA to San Francisco, CA arrived 15 or more minutes late, was diverted or was cancelled on 50% of 250 scheduled flights between September 2025 and August 2026. 1.2% were cancelled.

Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check Alaska Airlines for today's flight. Method.