Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 7 nonstops

Fri, Oct 9: WN 3905 at 08:30 is the safest bet, 8% chance of being 15+ min late; evening flights run 14–32%.

Safest bet that day WN 3905 STL 08:30 → DCA 11:25 · 8% chance 15+ min late · usually 84% on time Riskiest WN 3908 STL 19:55 → DCA 22:55 · 32% chance 15+ min late · usually 43% 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 3905 Southwest Flight history →	STL 08:30	DCA 11:25	8%	2%	0.6%	84%
AA 309 American Flight history →	STL 06:43	DCA 09:46	10%	3%	0.8%	91%
AA 5413 American flown by PSA Flight history →	STL 10:31	DCA 13:44	13%	6%	1.0%	76%
AA 4468 American flown by Republic Flight history →	STL 17:02	DCA 20:15	14%	7%	1.1%	50%
WN 2084 Southwest Flight history →	STL 13:20	DCA 16:20	22%	5%	0.6%	58%
WN 3907 Southwest Flight history →	STL 15:30	DCA 18:30	25%	7%	0.6%	52%
WN 3908 Southwest Flight history →	STL 19:55	DCA 22:55	32%	8%	0.6%	43%

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