Thursday, October 8 · typical odds for a Thursday (too early for a weather forecast) · issued Sun 12:00 PM ET · 4 nonstops

Thu, Oct 8 looks like a normal day here: all 4 nonstops are 18–24% likely to arrive 15+ min late.

Safest bet that day DL 541 SEA 16:05 → IAD 00:08 · 18% chance 15+ min late · usually 77% on time Riskiest AS 737 SEA 09:13 → IAD 17:11 · 24% chance 15+ min late · usually 84% on time

Every nonstop on Thu, Oct 8

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.


DL 541 Delta Flight history →	SEA 16:05	IAD 00:08	18%	5%	0.5%	77%
UA 1523 United	SEA 08:20	IAD 16:12	19%	5%	0.6%	no record
AS 675 Alaska	SEA 15:54	IAD 23:39	21%	4%	0.6%	no record
AS 737 Alaska Flight history →	SEA 09:13	IAD 17:11	24%	5%	0.6%	84%

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 Thu, Oct 8 (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