Today looks like a normal day here: all 4 nonstops are 15–23% likely to arrive 15+ min late.

Safest bet today DL 558 SEA 11:29 → CVG 18:47 · 15% chance 15+ min late · usually 89% on time Riskiest AS 520 SEA 13:47 → CVG 21:02 · 23% chance 15+ min late

Against a calm day 20% average chance a nonstop arrives 15+ min late; 20% 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.


DL 558 Delta Flight history →	SEA 11:29	CVG 18:47	15%	3%	0.2%	89%
AS 508 Alaska Flight history →	SEA 08:39	CVG 16:04	20%	2%	0.3%	83%
AS 298 Alaska Flight history →	SEA 22:05	CVG 05:30	20%	2%	0.7%	86%
AS 520 Alaska	SEA 13:47	CVG 21:02	23%	4%	0.3%	no record

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