Today looks rough: weather pushes the average chance of arriving 15+ min late to 42%, against 31% on a calm day. Safest: UA 1779 at 21:41, 24%.

Safest bet today UA 1779 ORD 21:41 → BOS 01:14 · 24% chance 15+ min late · usually 68% on time Riskiest B6 1012 ORD 20:10 → BOS 23:41 · 51% chance 15+ min late · usually 71% on time

Weather 42% average chance a nonstop arrives 15+ min late; 31% 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. 24 flights that already left today are not shown.


UA 1779 United Flight history →	ORD 21:41	BOS 01:14	24%	7%	0.5%	68%
AA 2682 American Flight history →	ORD 20:29	BOS 00:05	30%	9%	0.6%	62%
AA 2303 American Flight history →	ORD 15:08	BOS 18:47	37%	13%	0.6%	49%
DL 2816 Delta Flight history →	ORD 15:19	BOS 18:59	39%	11%	0.4%	62%
AA 1162 American	ORD 15:59	BOS 19:47	42%	14%	0.6%	no record
UA 1365 United	ORD 20:14	BOS 23:42	42%	14%	0.3%	no record
UA 487 United	ORD 15:58	BOS 19:39	43%	14%	0.3%	no record
DL 2646 Delta Flight history →	ORD 19:25	BOS 23:01	46%	13%	0.5%	65%worse than usual
AA 1461 American Flight history →	ORD 17:21	BOS 21:00	46%	18%	0.6%	46%
AA 3107 American Flight history →	ORD 19:29	BOS 23:06	46%	14%	0.6%	56%
UA 2331 United Flight history →	ORD 18:20	BOS 21:56	46%	16%	0.3%	59%
UA 1032 United Flight history →	ORD 19:45	BOS 23:21	47%	13%	0.3%	60%
AA 407 American Flight history →	ORD 17:19	BOS 20:42	48%	17%	0.6%	44%
B6 1012 JetBlue Flight history →	ORD 20:10	BOS 23:41	51%	19%	0.6%	71%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 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