Today looks rough: weather pushes the average chance of arriving 15+ min late to 47%, against 27% on a calm day. Safest: DL 3857 at 17:37, 39%.

Safest bet today DL 3857 GEG 17:37 → SEA 19:01 · 39% chance 15+ min late · usually 93% on time Riskiest AS 371 GEG 19:45 → SEA 20:59 · 56% chance 15+ min late · usually 45% on time

Weather 47% 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. 22 flights that already left today are not shown.


DL 3857 Delta flown by SkyWest Flight history →	GEG 17:37	SEA 19:01	39%	8%	0.5%	93%worse than usual
DL 3832 Delta flown by SkyWest Flight history →	GEG 19:59	SEA 21:22	42%	9%	0.5%	89%worse than usual
OO 3221 SkyWest	GEG 17:46	SEA 19:03	44%	8%	0.5%	no record
AS 3306 Alaska flown by SkyWest Flight history →	GEG 17:44	SEA 19:03	45%	8%	0.5%	86%worse than usual
AS 319 Alaska Flight history →	GEG 19:46	SEA 20:55	55%	10%	0.6%	88%worse than usual
AS 371 Alaska Flight history →	GEG 19:45	SEA 20:59	56%	10%	0.6%	45%

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 Sun, Oct 4 (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