Today looks rough: weather pushes the average chance of arriving 15+ min late to 46%, against 34% on a calm day. Safest: OO 3910 at 22:50, 37%.

Safest bet today OO 3910 SEA 22:50 → PDX 23:59 · 37% chance 15+ min late Riskiest AS 415 SEA 21:28 → PDX 21:56 · 58% chance 15+ min late

Weather 46% average chance a nonstop arrives 15+ min late; 34% 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. Dimmed: airlines we don’t forecast yet, shown with their 12-month record if they usually fly that weekday. 22 flights that already left today are not shown.


OO 3910 SkyWest	SEA 22:50	PDX 23:59	37%	9%	0.4%	no record
DL 4472 Delta flown by SkyWest Flight history →	SEA 22:50	PDX 23:54	38%	10%	0.4%	67%
AS 1495 Alaska	SEA 22:03	PDX 23:02	46%	12%	0.6%	no record
DL 3913 Delta flown by SkyWest Flight history →	SEA 20:59	PDX 22:00	47%	17%	0.4%	85%worse than usual
AS 1457 Alaska Flight history →	SEA 22:29	PDX 23:30	47%	11%	0.6%	67%worse than usual
AS 498 Alaska Flight history →	SEA 21:28	PDX 22:25	49%	12%	0.6%	74%worse than usual
AS 415 Alaska	SEA 21:28	PDX 21:56	58%	14%	0.6%	no record
AS 2377 Alaska flown by Horizon no forecast: 12-month record	SEA 23:26	PDX 00:22	14%	5%	4.5%	86%

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