Today: DL 786 at 07:20 is the safest bet, 11% chance of being 15+ min late; the others run 31–33%.

Safest bet today DL 786 SEA 07:20 → DCA 15:21 · 11% chance 15+ min late · usually 91% on time Riskiest AS 2 SEA 13:46 → DCA 21:59 · 33% chance 15+ min late · usually 70% on time

Against a calm day 25% average chance a nonstop arrives 15+ min late; 25% 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.


DL 786 Delta Flight history →	SEA 07:20	DCA 15:21	11%	3%	0.2%	91%
AS 4 Alaska Flight history →	SEA 08:00	DCA 16:16	31%	7%	0.4%	86%worse than usual
AS 2 Alaska Flight history →	SEA 13:46	DCA 21:59	33%	10%	0.4%	70%

Alternatives with one stop that day

All connections →


Southwest Details →	SEA 05:30 → MDW 11:25WN 2810	1h 20m Chicago	MDW 12:45 → DCA 15:35WN 2761	7h 05m	100%	82%
Southwest Details →	SEA 09:00 → STL 14:50WN 3632	1h 05m St Louis	STL 15:55 → DCA 19:05WN 3619	7h 05m	85%	73%
American Details →	SEA 06:00 → ORD 12:12AA 2922	1h 08m Chicago	ORD 13:20 → DCA 16:25AA 1675	7h 25m	90%	69%

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