Today: DL 1763 at 07:30 is the safest bet, 5% chance of being 15+ min late; the others run 7–36%.

Safest bet today DL 1763 SJU 07:30 → ATL 11:14 · 5% chance 15+ min late · usually 96% on time Riskiest F9 2871 SJU 06:26 → ATL 10:27 · 36% chance 15+ min late · usually 54% on time

Against a calm day 13% average chance a nonstop arrives 15+ min late; 10% 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.


DL 1763 Delta Flight history →	SJU 07:30	ATL 11:14	5%	2%	2.2%	96%
DL 1879 Delta Flight history →	SJU 06:00	ATL 09:45	7%	3%	2.2%	96%
DL 1882 Delta Flight history →	SJU 14:42	ATL 18:36	8%	3%	0.8%	87%
DL 1946 Delta Flight history →	SJU 17:50	ATL 21:49	10%	3%	0.8%	88%
DL 1930 Delta Flight history →	SJU 12:58	ATL 16:56	12%	5%	2.2%	88%
DL 1757 Delta Flight history →	SJU 12:50	ATL 16:40	13%	5%	2.2%	92%
F9 2871 Frontier Flight history →	SJU 06:26	ATL 10:27	36%	9%	3.4%	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