Today looks rough: weather pushes the average chance of arriving 15+ min late to 41%, against 25% on a calm day. Safest: B6 562 at 06:00, 31%.

Safest bet today B6 562 SJU 06:00 → BOS 10:05 · 31% chance 15+ min late · usually 80% on time Riskiest B6 762 SJU 16:55 → BOS 21:02 · 52% chance 15+ min late · usually 62% on time

Weather 41% average chance a nonstop arrives 15+ min late; 25% 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.


B6 562 JetBlue Flight history →	SJU 06:00	BOS 10:05	31%	14%	3.4%	80%worse than usual
DL 1780 Delta Flight history →	SJU 14:08	BOS 18:19	35%	15%	2.7%	80%worse than usual
B6 462 JetBlue Flight history →	SJU 20:07	BOS 00:13	37%	22%	1.2%	58%
B6 2962 JetBlue	SJU 16:15	BOS 20:37	51%	27%	4.3%	no record
B6 762 JetBlue Flight history →	SJU 16:55	BOS 21:02	52%	30%	4.4%	62%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