Today looks rough: weather pushes the average chance of arriving 15+ min late to 34%, against 18% on a calm day. Safest: WN 578 at 20:05, 26%.

Safest bet today WN 578 TPA 20:05 → SJU 23:14 · 26% chance 15+ min late Riskiest F9 2216 TPA 21:35 → SJU 00:41 · 45% chance 15+ min late · usually 69% on time

Weather 34% average chance a nonstop arrives 15+ min late; 18% 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. 1 flight that already left today is not shown.


WN 578 Southwest	TPA 20:05	SJU 23:14	26%	8%	0.4%	no record
WN 4047 Southwest Flight history →	TPA 20:35	SJU 23:40	30%	9%	0.7%	24%
B6 1751 JetBlue Flight history →	TPA 13:20	SJU 16:36	31%	14%	0.6%	73%
B6 2851 JetBlue Flight history →	TPA 14:19	SJU 17:21	35%	15%	0.6%	71%
B6 751 JetBlue Flight history →	TPA 21:10	SJU 00:14	35%	16%	0.9%	65%
F9 3980 Frontier Flight history →	TPA 20:46	SJU 00:07	37%	14%	1.9%	71%
F9 2216 Frontier Flight history →	TPA 21:35	SJU 00:41	45%	17%	1.6%	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 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