Today: WN 2585 at 08:05 is the safest bet, 7% chance of being 15+ min late; evening flights run 20%.

Safest bet today WN 2585 MCI 08:05 → STL 09:10 · 7% chance 15+ min late · usually 92% on time Riskiest WN 4341 MCI 18:10 → STL 19:15 · 20% chance 15+ min late · usually 57% on time

Against a calm day 13% 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 2585 Southwest Flight history →	MCI 08:05	STL 09:10	7%	1%	0.1%	92%
WN 2660 Southwest	MCI 08:36	STL 09:49	7%	1%	0.1%	no record
WN 2083 Southwest Flight history →	MCI 13:45	STL 14:50	12%	2%	0.2%	90%
WN 4562 Southwest	MCI 13:50	STL 15:04	14%	2%	0.1%	no record
WN 2975 Southwest	MCI 18:00	STL 19:14	20%	3%	0.2%	no record
WN 4341 Southwest Flight history →	MCI 18:10	STL 19:15	20%	3%	0.2%	57%

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