Today looks rough: weather pushes the average chance of arriving 15+ min late to 40%, against 27% on a calm day. Safest: 9K 5161 at 14:39, 26%.

Safest bet today 9K 5161 ACK 14:39 → BOS 15:17 · 26% chance 15+ min late Riskiest B6 1351 ACK 18:02 → BOS 18:56 · 64% chance 15+ min late · usually 70% on time

Weather 40% 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. 11 flights that already left today are not shown.


9K 5161 Cape Air	ACK 14:39	BOS 15:17	26%	8%	2.3%	no record
9K 5261 Cape Air	ACK 15:20	BOS 16:30	28%	11%	2.2%	no record
9K 5061 Cape Air	ACK 15:05	BOS 15:40	31%	8%	2.3%	no record
9K 5381 Cape Air	ACK 21:30	BOS 22:07	33%	14%	2.3%	no record
9K 5201 Cape Air	ACK 15:50	BOS 16:26	35%	13%	2.2%	no record
9K 5341 Cape Air	ACK 16:50	BOS 17:26	35%	14%	2.3%	no record
9K 5621 Cape Air	ACK 20:00	BOS 20:36	37%	14%	2.2%	no record
9K 5361 Cape Air	ACK 18:10	BOS 18:45	42%	14%	2.3%	no record
9K 5601 Cape Air	ACK 17:30	BOS 18:06	45%	15%	2.2%	no record
B6 1151 JetBlue Flight history →	ACK 15:33	BOS 16:26	63%	30%	1.8%	67%worse than usual
B6 1351 JetBlue Flight history →	ACK 18:02	BOS 18:56	64%	30%	2.1%	70%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 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