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 1243 at 05:10 is the safest bet, 5% chance of being 15+ min late; the others run 23–28%.

Safest bet that day WN 1243 RSW 05:10 → MDW 07:00 · 5% chance 15+ min late · usually 96% on time Riskiest WN 4120 RSW 17:10 → MDW 19:05 · 28% chance 15+ min late · usually 41% 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 1243 Southwest Flight history →	RSW 05:10	MDW 07:00	5%	1%	4.0%	96%
WN 3469 Southwest Flight history →	RSW 11:40	MDW 13:30	23%	5%	5.1%	81%
WN 4120 Southwest Flight history →	RSW 17:10	MDW 19:05	28%	12%	7.1%	41%

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