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 1340 at 10:40 is the safest bet, 20% chance of being 15+ min late; evening flights run 32–33%.

Safest bet that day WN 1340 MDW 10:40 → SEA 13:10 · 20% chance 15+ min late · usually 50% on time Riskiest WN 2890 MDW 17:15 → SEA 19:45 · 33% chance 15+ min late · usually 27% 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 1340 Southwest Flight history →	MDW 10:40	SEA 13:10	20%	3%	0.6%	50%
WN 4144 Southwest Flight history →	MDW 22:00	SEA 00:35	32%	7%	0.6%	57%
WN 2890 Southwest Flight history →	MDW 17:15	SEA 19:45	33%	9%	0.6%	27%

Alternatives with one stop that day

All connections →


Southwest Details →	MDW 05:15 → DEN 06:50WN 2989	55m Denver	DEN 07:45 → SEA 09:45WN 1713	6h 30m	97%	81%
Southwest Details →	MDW 09:55 → DEN 11:30WN 2654	1h 00m Denver	DEN 12:30 → SEA 14:25WN 4130	6h 30m	90%	59%

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