Today: AA 3329 at 05:52 is the safest bet, 5% chance of being 15+ min late; evening flights run 8–14%.

Safest bet today AA 3329 PDX 05:52 → ORD 11:50 · 5% chance 15+ min late · usually 89% on time Riskiest AA 2515 PDX 13:12 → ORD 19:23 · 18% chance 15+ min late · usually 82% on time

Against a calm day 10% average chance a nonstop arrives 15+ min late; 12% 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.


AA 3329 American Flight history →	PDX 05:52	ORD 11:50	5%	2%	0.6%	89%
AA 1713 American	PDX 06:01	ORD 12:09	5%	2%	0.6%	no record
UA 2306 United Flight history →	PDX 07:00	ORD 13:13	7%	2%	0.3%	91%
UA 2822 United	PDX 08:24	ORD 14:30	8%	3%	0.3%	no record
UA 2094 United Flight history →	PDX 23:28	ORD 05:41	8%	3%	0.5%	90%
UA 1923 United	PDX 10:43	ORD 16:50	10%	3%	0.3%	no record
AS 324 Alaska Flight history →	PDX 07:00	ORD 13:13	10%	2%	0.7%	74%
UA 2266 United	PDX 14:25	ORD 20:31	11%	3%	0.3%	no record
AA 1813 American	PDX 23:03	ORD 05:09	12%	6%	1.8%	no record
AA 1094 American	PDX 23:09	ORD 05:06	14%	6%	1.8%	no record
AA 2515 American Flight history →	PDX 13:12	ORD 19:23	18%	4%	0.5%	82%

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 Tue, Oct 6 (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