Today looks like a normal day here: all 4 nonstops are 18–25% likely to arrive 15+ min late.

Safest bet today AS 504 SEA 19:58 → STS 21:56 · 18% chance 15+ min late Riskiest AS 3410 SEA 20:44 → STS 22:51 · 25% chance 15+ min late · usually 68% on time

Against a calm day 23% average chance a nonstop arrives 15+ min late; 19% for the same flights on a calm-weather day

Every nonstop today

12-month record →

Ranked by the chance of arriving 15+ minutes late, with each flight’s on-time record over Aug 2025 – Jul 2026 beside it. Times are local. Pick a flight for its forecast. Click a column to sort.


AS 504 Alaska	SEA 19:58	STS 21:56	18%	3%	0.9%	no record
AS 1321 Alaska Flight history →	SEA 09:54	STS 11:58	23%	4%	0.6%	83%
AS 1347 Alaska	SEA 10:58	STS 12:57	25%	6%	0.6%	no record
AS 3410 Alaska flown by SkyWest Flight history →	SEA 20:44	STS 22:51	25%	7%	2.1%	68%

How these are worked out. Each flight’s odds are our forecast for that day; flights of airlines we don’t forecast yet use their 12-month record and are marked. Makes the connection: the first flight’s 12-month lateness curve, scaled so its chance of arriving 15+ min late matches the day’s forecast, at the layover minus the 45-minute minimum (90 on separate tickets). Arrives on time: first flight not cancelled × connection made × second flight not cancelled × second flight within 15 minutes, each from the day’s forecast.

About this data: forecast odds from our model for Mon, Oct 5 (newest published update); 12-month records from US DOT on-time data, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. JSON