ON TIMEBOARD

AS 337 on time

Alaska Airlines 337: Chicago to Seattle at 5:42 p.m. (past 12 months)

On time
46%
186 flights · likely 39–53%
Cancelled
6.5%
of scheduled flights
Typical arrival
+16 min
median vs schedule
When late
+75 min
average delay
Similar flights
51%
AS, same route & hour

About 5 in 10 AS 337 flights from Chicago arrived 15+ minutes late, diverted or cancelled over the past year (54%); 6.5% were cancelled. The typical flight landed 16 minutes late.

AS 337: ORD → SEA

Scheduled to leave Chicago at 5:42 p.m. local time. Over the past year it arrived on time 46% of the time (186 flights), worse than other AS flights on the route at that hour (51%). Last seen in the data Aug 31, 2026.

Usually Alaska Airlines's last flight of the day from Chicago to Seattle (68% of days). Alaska Airlines's last ORD–SEA flight was cancelled 4.1% of the time, against 1.2% for its earlier ones. If it's cancelled, the next Alaska Airlines flight is usually around 6:00 a.m. the next morning.

Month by month

20%60%100%May 2025: too few flights (14 flights)MayJun 2025: 53% on time (19 flights)53JunJul 2025: 37% on time (30 flights)37JulAug 2025: 32% on time (31 flights)32AugSep 2025: 43% on time (30 flights)43SepOct 2025: 52% on time (29 flights)52OctNov 2025: 40% on time (20 flights)40NovDec 2025: 43% on time (28 flights)43DecJan 2026: too few flights (6 flights)JanJun 2026: 50% on time (18 flights)50JunJul 2026: 56% on time (27 flights)56JulAug 2026: 39% on time (28 flights)39Aug

By day of week

DayFlightsOn time
Monday3148%
Tuesday2552%
Wednesday2646%
Thursday2836%
Friday3047%
Saturday2157%
Sunday2540%

Why it was late

Late inbound plane 62%Air traffic & airport (NAS) 24%Airline (crew, maintenance, ops) 13%Severe weather 1%

All flights ORD → SEA · Connecting off AS 337? Check the risk

Questions

How often is AS 337 from ORD to SEA late?

Alaska Airlines 337 from Chicago, IL to Seattle, WA arrived 15 or more minutes late, was diverted or was cancelled on 54% of 186 scheduled flights between September 2025 and August 2026. 6.5% 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.