Today: AA 4728 at 18:59 is the safest bet, 48% chance of being 15+ min late; the others run 60–63%.

Safest bet today AA 4728 LGA 18:59 → STL 20:55 · 48% chance 15+ min late · usually 67% on time Riskiest WN 2552 LGA 18:30 → STL 20:11 · 63% chance 15+ min late

Against a calm day 57% average chance a nonstop arrives 15+ min late; 57% 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. Dimmed: airlines we don’t forecast yet, shown with their 12-month record if they usually fly that weekday. 11 flights that already left today are not shown.


AA 4728 American flown by Republic Flight history →	LGA 18:59	STL 20:55	48%	17%	0.8%	67%worse than usual
WN 4895 Southwest Flight history →	LGA 18:35	STL 20:35	60%	19%	0.7%	49%
WN 2552 Southwest	LGA 18:30	STL 20:11	63%	19%	0.6%	no record
DL 4926 Delta flown by Endeavor no forecast: 12-month record	LGA 18:51	STL 20:46	30%	14%	9.5%	70%

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