Today: AA 4645 at 11:23 is the safest bet, 10% chance of being 15+ min late; evening flights run 15–28%.

Safest bet today AA 4645 STL 11:23 → DCA 14:47 · 10% chance 15+ min late · usually 80% on time Riskiest WN 3908 STL 19:55 → DCA 22:55 · 28% chance 15+ min late · usually 43% on time

Against a calm day 16% average chance a nonstop arrives 15+ min late; 18% for the same flights on a calm-weather day

Every nonstop today

12-month record →

Ranked by the chance of arriving 15+ minutes late, 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. 4 flights that already left today are not shown.


AA 4645 American flown by Republic Flight history →	STL 11:23	DCA 14:47	10%	4%	0.2%	80%
YX 4508 Republic	STL 13:26	DCA 16:50	10%	4%	0.2%	no record
WN 3522 Southwest	STL 13:15	DCA 16:25	11%	4%	0.2%	no record
WN 2084 Southwest Flight history →	STL 13:20	DCA 16:20	12%	4%	0.2%	58%
WN 3619 Southwest	STL 15:55	DCA 19:05	14%	4%	0.2%	no record
AA 2030 American	STL 17:11	DCA 20:32	15%	9%	0.4%	no record
WN 3907 Southwest Flight history →	STL 15:30	DCA 18:30	15%	4%	0.2%	52%
AA 4468 American flown by Republic Flight history →	STL 17:02	DCA 20:15	15%	6%	0.4%	50%
AA 5413 American flown by PSA Flight history →	STL 10:31	DCA 13:44	20%	9%	1.3%	76%
WN 3732 Southwest	STL 19:50	DCA 22:59	25%	8%	0.6%	no record
WN 3908 Southwest Flight history →	STL 19:55	DCA 22:55	28%	8%	0.6%	43%

How these are worked out. Each flight’s odds are our forecast for that day; 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 Mon, Oct 5 (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