Today: UA 8223 at 23:16 is the safest bet, 26% chance of being 15+ min late; the others run 28–39%.

Safest bet today UA 8223 SEA 23:16 → IAD 07:35 · 26% chance 15+ min late Riskiest AS 367 SEA 22:43 → IAD 06:39 · 39% chance 15+ min late · usually 84% on time

Against a calm day 31% average chance a nonstop arrives 15+ min late; 23% 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. 7 flights that already left today are not shown.


UA 8223 United	SEA 23:16	IAD 07:35	26%	13%	0.6%	no record
UA 264 United Flight history →	SEA 23:20	IAD 07:22	28%	11%	0.7%	91%worse than usual
AS 367 Alaska Flight history →	SEA 22:43	IAD 06:39	39%	8%	0.6%	84%worse than usual

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 Sun, Oct 4 (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