Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 6 nonstops

Fri, Oct 9: WN 3919 at 05:00 is the safest bet, 3% chance of being 15+ min late; evening flights run 24–29%.

Safest bet that day WN 3919 STL 05:00 → HOU 07:05 · 3% chance 15+ min late · usually 91% on time Riskiest WN 4617 STL 21:45 → HOU 23:50 · 29% chance 15+ min late · usually 52% 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 3919 Southwest Flight history →	STL 05:00	HOU 07:05	3%	1%	1.4%	91%
WN 3928 Southwest Flight history →	STL 07:15	HOU 09:20	5%	2%	1.2%	88%
WN 4752 Southwest Flight history →	STL 13:50	HOU 15:55	20%	4%	1.2%	50%
WN 5065 Southwest Flight history →	STL 17:40	HOU 19:45	24%	6%	0.9%	73%
WN 3136 Southwest Flight history →	STL 18:50	HOU 20:55	26%	6%	0.8%	62%
WN 4617 Southwest Flight history →	STL 21:45	HOU 23:50	29%	6%	0.7%	52%

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