Today: AA 3556 at 11:31 is the safest bet, 14% chance of being 15+ min late; evening flights run 21–30%.

Safest bet today AA 3556 GSP 11:31 → ORD 12:40 · 14% chance 15+ min late · usually 86% on time Riskiest UA 5524 GSP 17:43 → ORD 19:00 · 30% chance 15+ min late · usually 61% on time

Against a calm day 20% average chance a nonstop arrives 15+ min late; 20% 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. 2 flights that already left today are not shown.


AA 3556 American flown by Envoy Flight history →	GSP 11:31	ORD 12:40	14%	3%	0.2%	86%
AA 4160 American flown by Envoy Flight history →	GSP 11:47	ORD 12:56	14%	3%	0.2%	89%
AA 3564 American flown by Envoy Flight history →	GSP 08:14	ORD 09:31	16%	3%	0.3%	79%
UA 5361 United flown by SkyWest Flight history →	GSP 10:45	ORD 11:59	21%	6%	0.2%	66%
AA 3559 American flown by Envoy Flight history →	GSP 19:20	ORD 20:51	21%	4%	0.4%	70%
AA 4145 American flown by Envoy Flight history →	GSP 18:52	ORD 20:01	26%	5%	0.3%	59%
UA 5524 United flown by SkyWest Flight history →	GSP 17:43	ORD 19:00	30%	9%	0.3%	61%

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