Today: WN 2667 at 08:30 is the safest bet, 5% chance of being 15+ min late; evening flights run 14–21%.

Safest bet today WN 2667 STL 08:30 → MCI 09:46 · 5% chance 15+ min late Riskiest WN 3944 STL 16:45 → MCI 17:50 · 21% chance 15+ min late · usually 54% on time

Against a calm day 12% 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 2667 Southwest	STL 08:30	MCI 09:46	5%	1%	0.2%	no record
WN 3943 Southwest Flight history →	STL 08:10	MCI 09:15	5%	1%	0.2%	94%
WN 487 Southwest	STL 15:05	MCI 16:22	12%	4%	0.2%	no record
WN 4964 Southwest	STL 21:50	MCI 23:07	14%	3%	0.5%	no record
WN 2453 Southwest Flight history →	STL 21:45	MCI 22:55	15%	3%	0.5%	60%
WN 3944 Southwest Flight history →	STL 16:45	MCI 17:50	21%	7%	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