Monday, October 5 · our forecast odds · issued Sun 4:00 PM ET · 7 nonstops

Tomorrow: WN 3555 at 07:50 is the safest bet, 6% chance of being 15+ min late; the others run 8–18%.

Safest bet that day WN 3555 MDW 07:50 → STL 09:06 · 6% chance 15+ min late Riskiest WN 2904 MDW 18:00 → STL 19:10 · 18% chance 15+ min late · usually 70% on time

Against a calm day 13% average chance a nonstop arrives 15+ min late; 13% for the same flights on a calm-weather day

Every nonstop on Mon, Oct 5

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 3555 Southwest	MDW 07:50	STL 09:06	6%	2%	0.5%	no record
WN 806 Southwest	MDW 10:58	STL 12:14	8%	2%	0.5%	no record
WN 2902 Southwest Flight history →	MDW 13:00	STL 14:10	13%	2%	0.5%	78%
WN 2901 Southwest Flight history →	MDW 11:00	STL 12:10	13%	2%	0.5%	75%
WN 884 Southwest	MDW 14:45	STL 16:02	16%	3%	0.5%	no record
WN 2903 Southwest Flight history →	MDW 14:45	STL 15:55	17%	3%	0.5%	62%
WN 2904 Southwest Flight history →	MDW 18:00	STL 19:10	18%	4%	0.5%	70%

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