Today looks like a normal day here: all 3 nonstops are 31–38% likely to arrive 15+ min late.

Safest bet today AA 4423 LGA 15:08 → GSP 17:29 · 31% chance 15+ min late · usually 68% on time Riskiest AA 4787 LGA 20:27 → GSP 22:39 · 38% chance 15+ min late · usually 71% on time

Against a calm day 33% average chance a nonstop arrives 15+ min late; 26% 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. 2 flights that already left today are not shown.


AA 4423 American flown by Republic Flight history →	LGA 15:08	GSP 17:29	31%	11%	0.6%	68%
AA 4534 American flown by Republic Flight history →	LGA 15:28	GSP 17:48	31%	10%	0.6%	78%
AA 4787 American flown by Republic Flight history →	LGA 20:27	GSP 22:39	38%	15%	1.0%	71%
DL 4996 Delta flown by Endeavor no forecast: 12-month record	LGA 20:15	GSP 22:35	29%	15%	11.6%	71%
DL 5004 Delta flown by Endeavor no forecast: 12-month record	LGA 15:10	GSP 17:30	34%	14%	5.4%	66%

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