Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 3 nonstops

Fri, Oct 9: WN 4154 at 07:35 is the safest bet, 6% chance of being 15+ min late; evening flights run 20–24%.

Safest bet that day WN 4154 BUF 07:35 → MDW 08:15 · 6% chance 15+ min late · usually 100% on time Riskiest WN 768 BUF 19:55 → MDW 20:35 · 24% chance 15+ min late · usually 60% on time

Every nonstop on Fri, Oct 9

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 4154 Southwest Flight history →	BUF 07:35	MDW 08:15	6%	1%	0.6%	100%
WN 766 Southwest Flight history →	BUF 16:10	MDW 16:50	20%	5%	0.7%	56%
WN 768 Southwest Flight history →	BUF 19:55	MDW 20:35	24%	6%	1.1%	60%

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 Fri, Oct 9 (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