Monday, October 5 · our forecast odds · issued Sun 4:00 PM ET · 8 nonstops

Tomorrow: DL 541 at 16:05 is the safest bet, 16% chance of being 15+ min late; morning flights run 19–21%.

Safest bet that day DL 541 SEA 16:05 → IAD 00:08 · 16% chance 15+ min late · usually 77% on time Riskiest AS 737 SEA 09:13 → IAD 17:11 · 26% chance 15+ min late · usually 84% on time

Against a calm day 20% average chance a nonstop arrives 15+ min late; 17% for the same flights on a calm-weather day

Every nonstop on Mon, Oct 5

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 541 Delta Flight history →	SEA 16:05	IAD 00:08	16%	4%	0.7%	77%
AS 406 Alaska Flight history →	SEA 16:01	IAD 23:59	18%	3%	0.6%	81%
UA 264 United Flight history →	SEA 23:20	IAD 07:22	19%	4%	0.7%	91%
UA 2463 United Flight history →	SEA 08:15	IAD 16:24	19%	4%	0.6%	92%worse than usual
UA 2131 United Flight history →	SEA 13:00	IAD 21:06	20%	5%	0.6%	93%worse than usual
UA 1523 United	SEA 08:33	IAD 16:43	21%	5%	0.6%	no record
AS 367 Alaska Flight history →	SEA 22:43	IAD 06:39	22%	3%	0.6%	84%
AS 737 Alaska Flight history →	SEA 09:13	IAD 17:11	26%	5%	0.6%	84%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