Today: WN 4884 at 07:10 is the safest bet, 4% chance of being 15+ min late; evening flights run 13–16%.

Safest bet today WN 4884 CMH 07:10 → STL 07:48 · 4% chance 15+ min late Riskiest WN 2614 CMH 20:35 → STL 21:00 · 16% chance 15+ min late · usually 63% on time

Against a calm day 9% average chance a nonstop arrives 15+ min late; 10% 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.


WN 4884 Southwest	CMH 07:10	STL 07:48	4%	1%	0.2%	no record
WN 1207 Southwest Flight history →	CMH 07:05	STL 07:30	4%	1%	0.2%	100%
WN 4925 Southwest	CMH 20:30	STL 21:06	13%	4%	0.4%	no record
WN 2614 Southwest Flight history →	CMH 20:35	STL 21:00	16%	4%	0.4%	63%

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