Wednesday, October 7 · typical odds for a Wednesday (too early for a weather forecast) · issued Sat 12:00 PM ET · 6 nonstops

Wed, Oct 7 looks like a normal day here: all 6 nonstops are 6–13% likely to arrive 15+ min late.

Safest bet that day WN 2837 MDW 08:11 → STL 09:23 · 6% chance 15+ min late Riskiest WN 4254 MDW 20:28 → STL 21:41 · 13% chance 15+ min late

Every nonstop on Wed, Oct 7

12-month record →

Ranked by the chance of arriving 15+ minutes late (typical odds: the weather this date has had in past years), 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 2837 Southwest	MDW 08:11	STL 09:23	6%	2%	0.9%	no record
WN 8628 Southwest	MDW 03:15	STL 04:28	7%	2%	1.1%	no record
WN 3877 Southwest	MDW 10:15	STL 11:27	8%	2%	0.8%	no record
WN 591 Southwest	MDW 14:02	STL 15:14	10%	3%	0.7%	no record
WN 126 Southwest	MDW 16:38	STL 17:50	12%	3%	0.6%	no record
WN 4254 Southwest	MDW 20:28	STL 21:41	13%	3%	0.6%	no record

How these are worked out. Each flight’s odds are our forecast for that day (typical odds until the weather forecast covers it); 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 Wed, Oct 7 (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