Today looks like a normal day here: all 4 nonstops are 20–28% likely to arrive 15+ min late.

Safest bet today WN 4038 STL 21:45 → AUS 23:57 · 20% chance 15+ min late Riskiest WN 329 STL 15:20 → AUS 17:20 · 28% chance 15+ min late · usually 54% on time

Against a calm day 24% average chance a nonstop arrives 15+ min late; 16% 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. 2 flights that already left today are not shown.


WN 4038 Southwest	STL 21:45	AUS 23:57	20%	6%	0.5%	no record
WN 4515 Southwest Flight history →	STL 21:55	AUS 23:55	23%	6%	0.5%	51%
WN 3173 Southwest	STL 12:50	AUS 15:03	26%	6%	0.2%	no record
WN 329 Southwest Flight history →	STL 15:20	AUS 17:20	28%	6%	0.2%	54%

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