Today: AA 2933 at 06:07 is the safest bet, 8% chance of being 15+ min late; evening flights run 13–22%.

Safest bet today AA 2933 PDX 06:07 → ORD 12:17 · 8% chance 15+ min late · usually 83% on time Riskiest AA 2977 PDX 23:15 → ORD 05:14 · 22% chance 15+ min late · usually 63% on time

Against a calm day 16% average chance a nonstop arrives 15+ min late; 15% 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. 1 flight that already left today is not shown.


AA 2933 American Flight history →	PDX 06:07	ORD 12:17	8%	2%	0.2%	83%
AA 1713 American	PDX 05:59	ORD 12:03	8%	2%	0.2%	no record
UA 2306 United Flight history →	PDX 07:00	ORD 13:13	11%	3%	0.1%	91%
UA 2822 United	PDX 08:26	ORD 14:38	13%	3%	0.1%	no record
UA 1490 United Flight history →	PDX 23:40	ORD 05:45	13%	5%	0.6%	89%
AS 324 Alaska Flight history →	PDX 07:00	ORD 13:13	16%	3%	0.3%	74%
AA 3303 American Flight history →	PDX 13:45	ORD 19:50	16%	5%	0.2%	53%
UA 1923 United	PDX 10:40	ORD 16:43	17%	3%	0.1%	no record
AA 2284 American Flight history →	PDX 11:26	ORD 17:42	17%	4%	0.2%	70%
AA 2515 American Flight history →	PDX 13:18	ORD 19:30	17%	5%	0.2%	82%
UA 2266 United	PDX 14:22	ORD 20:25	18%	4%	0.1%	no record
UA 1641 United Flight history →	PDX 10:46	ORD 17:00	18%	4%	0.1%	76%
UA 2336 United Flight history →	PDX 14:25	ORD 20:38	18%	4%	0.1%	68%
AA 1813 American	PDX 22:53	ORD 04:58	19%	8%	1.6%	no record
AA 2977 American Flight history →	PDX 23:15	ORD 05:14	22%	8%	1.3%	63%

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