Today: B6 753 at 06:40 is the safest bet, 11% chance of being 15+ min late; evening flights run 22–33%.

Safest bet today B6 753 FLL 06:40 → SJU 09:19 · 11% chance 15+ min late · usually 87% on time Riskiest F9 3018 FLL 11:02 → SJU 13:57 · 39% chance 15+ min late · usually 57% on time

Against a calm day 30% 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 753 JetBlue Flight history →	FLL 06:40	SJU 09:19	11%	5%	0.4%	87%
WN 1931 Southwest	FLL 17:25	SJU 20:10	22%	5%	0.6%	no record
B6 153 JetBlue Flight history →	FLL 16:20	SJU 19:04	30%	11%	0.8%	67%
B6 553 JetBlue Flight history →	FLL 17:45	SJU 20:27	33%	13%	0.8%	85%worse than usual
B6 1553 JetBlue Flight history →	FLL 10:10	SJU 12:48	33%	8%	0.5%	60%
B6 2153 JetBlue Flight history →	FLL 20:37	SJU 23:20	33%	14%	0.8%	56%
B6 1453 JetBlue Flight history →	FLL 12:05	SJU 14:42	37%	14%	0.5%	71%
F9 3018 Frontier Flight history →	FLL 11:02	SJU 13:57	39%	19%	1.1%	57%

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