Today: YX 4508 at 11:24 is the safest bet, 13% chance of being 15+ min late; evening flights run 21–33%.

Safest bet today YX 4508 DCA 11:24 → STL 13:08 · 13% chance 15+ min late Riskiest WN 1462 DCA 18:40 → STL 20:00 · 33% chance 15+ min late · usually 49% on time

Against a calm day 22% average chance a nonstop arrives 15+ min late; 27% 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.


YX 4508 Republic	DCA 11:24	STL 13:08	13%	2%	0.3%	no record
WN 1521 Southwest	DCA 12:02	STL 13:29	14%	2%	0.2%	no record
WN 4752 Southwest Flight history →	DCA 12:00	STL 13:15	16%	2%	0.2%	75%
AA 4468 American flown by Republic Flight history →	DCA 15:00	STL 16:29	18%	3%	0.4%	61%
YX 4536 Republic	DCA 18:55	STL 20:41	21%	4%	0.4%	no record
WN 1522 Southwest	DCA 15:27	STL 16:55	21%	3%	0.2%	no record
AA 2030 American	DCA 14:33	STL 16:09	24%	7%	0.2%	no record
WN 1461 Southwest Flight history →	DCA 14:35	STL 15:50	24%	3%	0.2%	43%
AA 3028 American Flight history →	DCA 20:00	STL 21:21	30%	9%	0.2%	56%
WN 398 Southwest	DCA 18:50	STL 20:18	33%	5%	0.2%	no record
WN 1462 Southwest Flight history →	DCA 18:40	STL 20:00	33%	6%	0.2%	49%

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