Today looks rough: weather pushes the average chance of arriving 15+ min late to 69%, against 27% on a calm day. Safest: AA 4659 at 22:24, 52%.

Safest bet today AA 4659 JFK 22:24 → BOS 23:51 · 52% chance 15+ min late · usually 79% on time Riskiest B6 818 JFK 17:25 → BOS 18:59 · 79% chance 15+ min late · usually 69% on time

Weather 69% 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. 10 flights that already left today are not shown.


AA 4659 American flown by Republic Flight history →	JFK 22:24	BOS 23:51	52%	25%	1.8%	79%worse than usual
AA 4634 American flown by Republic Flight history →	JFK 21:35	BOS 22:59	60%	30%	2.4%	70%worse than usual
DL 2639 Delta Flight history →	JFK 21:00	BOS 22:43	64%	49%	1.2%	71%worse than usual
DL 5798 Delta flown by Republic Flight history →	JFK 17:30	BOS 19:15	72%	38%	2.1%	63%worse than usual
AA 4346 American flown by Republic Flight history →	JFK 17:30	BOS 19:06	72%	38%	2.2%	61%worse than usual
B6 1318 JetBlue Flight history →	JFK 22:29	BOS 23:59	74%	40%	1.3%	65%worse than usual
B6 2618 JetBlue Flight history →	JFK 16:35	BOS 18:07	79%	50%	1.1%	90%worse than usual
B6 818 JetBlue Flight history →	JFK 17:25	BOS 18:59	79%	49%	1.2%	69%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