Today: B6 754 at 05:35 is the safest bet, 12% chance of being 15+ min late; the others run 14–33%.

Safest bet today B6 754 SJU 05:35 → FLL 08:14 · 12% chance 15+ min late · usually 88% on time Riskiest B6 154 SJU 17:00 → FLL 19:42 · 33% chance 15+ min late · usually 54% on time

Against a calm day 22% average chance a nonstop arrives 15+ min late; 20% 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 754 JetBlue Flight history →	SJU 05:35	FLL 08:14	12%	6%	1.4%	88%
B6 1754 JetBlue Flight history →	SJU 07:00	FLL 09:40	14%	7%	1.4%	77%
WN 3897 Southwest	SJU 13:05	FLL 15:47	14%	5%	0.7%	no record
B6 2154 JetBlue Flight history →	SJU 09:42	FLL 12:23	23%	8%	1.3%	73%
F9 3017 Frontier Flight history →	SJU 06:00	FLL 08:48	24%	6%	3.0%	83%
B6 1454 JetBlue Flight history →	SJU 14:05	FLL 16:47	28%	9%	1.0%	70%
B6 54 JetBlue Flight history →	SJU 11:00	FLL 13:41	29%	8%	1.4%	74%
B6 154 JetBlue Flight history →	SJU 17:00	FLL 19:42	33%	10%	1.0%	54%

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