Today looks rough: weather pushes the average chance of arriving 15+ min late to 42%, against 28% on a calm day. Safest: DL 1114 at 21:20, 37%.

Safest bet today DL 1114 SEA 21:20 → PHL 05:29 · 37% chance 15+ min late · usually 85% on time Riskiest AA 2870 SEA 12:57 → PHL 21:18 · 53% chance 15+ min late · usually 70% on time

Weather 42% average chance a nonstop arrives 15+ min late; 28% 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.


DL 1114 Delta Flight history →	SEA 21:20	PHL 05:29	37%	7%	0.4%	85%worse than usual
AS 371 Alaska Flight history →	SEA 21:32	PHL 05:33	38%	7%	1.0%	90%worse than usual
AA 2522 American Flight history →	SEA 22:35	PHL 06:48	40%	7%	0.7%	86%worse than usual
AA 2886 American Flight history →	SEA 22:50	PHL 07:01	40%	8%	0.7%	88%worse than usual
AS 522 Alaska Flight history →	SEA 22:02	PHL 06:13	42%	9%	1.0%	88%worse than usual
AA 2870 American Flight history →	SEA 12:57	PHL 21:18	53%	14%	0.5%	70%worse than usual

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