Today: WN 1768 at 14:20 is the safest bet, 21% chance of being 15+ min late; the others run 23–35%.

Safest bet today WN 1768 DEN 14:20 → TYS 19:10 · 21% chance 15+ min late · usually 79% on time Riskiest F9 2374 DEN 14:34 → TYS 19:24 · 35% chance 15+ min late · usually 81% on time

Against a calm day 26% 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. 1 flight that already left today is not shown.


WN 1768 Southwest Flight history →	DEN 14:20	TYS 19:10	21%	8%	0.1%	79%
UA 2473 United Flight history →	DEN 17:25	TYS 22:19	23%	9%	0.2%	71%
WN 1826 Southwest	DEN 14:23	TYS 18:39	25%	8%	0.1%	no record
F9 2374 Frontier Flight history →	DEN 14:34	TYS 19:24	35%	19%	0.4%	81%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 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