Today looks rough: weather pushes the average chance of arriving 15+ min late to 41%, against 20% on a calm day. Safest: DL 1946 at 13:00, 30%.

Safest bet today DL 1946 ATL 13:00 → SJU 16:39 · 30% chance 15+ min late · usually 82% on time Riskiest F9 2082 ATL 11:44 → SJU 15:40 · 62% chance 15+ min late · usually 57% on time

Weather 41% 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. 2 flights that already left today are not shown.


DL 1946 Delta Flight history →	ATL 13:00	SJU 16:39	30%	4%	0.2%	82%worse than usual
DL 1882 Delta Flight history →	ATL 09:45	SJU 13:32	33%	4%	0.2%	78%worse than usual
DL 1791 Delta Flight history →	ATL 16:59	SJU 20:45	39%	5%	0.2%	66%
DL 1861 Delta Flight history →	ATL 18:45	SJU 22:29	40%	7%	0.2%	67%
F9 2082 Frontier Flight history →	ATL 11:44	SJU 15:40	62%	20%	1.0%	57%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