Today looks like a normal day here: all 3 nonstops are 18–23% likely to arrive 15+ min late.

Safest bet today AA 5130 GSP 08:00 → PHL 09:50 · 18% chance 15+ min late · usually 90% on time Riskiest OH 5423 GSP 08:21 → PHL 09:26 · 23% chance 15+ min late

Against a calm day 21% average chance a nonstop arrives 15+ min late; 25% 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.


AA 5130 American flown by PSA Flight history →	GSP 08:00	PHL 09:50	18%	9%	1.3%	90%
AA 5427 American flown by PSA Flight history →	GSP 18:12	PHL 20:11	23%	8%	0.9%	100%worse than usual
OH 5423 PSA	GSP 08:21	PHL 09:26	23%	8%	1.0%	no record
AA 5908 American flown by Piedmont no forecast: 12-month record	GSP 10:37	PHL 12:32	10%	4%	0.0%	90%
AA 5801 American flown by Piedmont no forecast: 12-month record	GSP 18:32	PHL 20:31	26%	19%	4.9%	74%
AA 6132 American flown by Piedmont no forecast: 12-month record	GSP 14:29	PHL 16:29	33%	15%	6.9%	67%

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