Today looks rough: weather pushes the average chance of arriving 15+ min late to 71%, against 48% on a calm day. Safest: DL 520 at 21:00, 60%.

Safest bet today DL 520 ATL 21:00 → LGA 23:24 · 60% chance 15+ min late · usually 72% on time Riskiest F9 3458 ATL 18:35 → LGA 20:57 · 87% chance 15+ min late · usually 34% on time

Weather 71% average chance a nonstop arrives 15+ min late; 48% 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. 19 flights that already left today are not shown.


DL 520 Delta Flight history →	ATL 21:00	LGA 23:24	60%	24%	1.0%	72%worse than usual
AA 4662 American flown by Republic Flight history →	ATL 19:18	LGA 21:40	62%	30%	1.1%	57%worse than usual
DL 434 Delta Flight history →	ATL 18:00	LGA 20:27	64%	20%	0.8%	64%worse than usual
DL 490 Delta Flight history →	ATL 20:00	LGA 22:27	68%	25%	0.7%	63%worse than usual
DL 468 Delta Flight history →	ATL 19:00	LGA 21:28	70%	29%	0.7%	67%worse than usual
F9 3288 Frontier Flight history →	ATL 20:22	LGA 22:43	85%	52%	2.7%	41%worse than usual
F9 3458 Frontier Flight history →	ATL 18:35	LGA 20:57	87%	52%	4.8%	34%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 Sun, Oct 4 (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