Today: WN 952 at 11:45 is the safest bet, 7% chance of being 15+ min late; evening flights run 20–21%.

Safest bet today WN 952 BWI 11:45 → GSP 13:15 · 7% chance 15+ min late · usually 59% on time Riskiest WN 2468 BWI 20:01 → GSP 21:43 · 21% chance 15+ min late

Against a calm day 14% average chance a nonstop arrives 15+ min late; 21% 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.


WN 952 Southwest Flight history →	BWI 11:45	GSP 13:15	7%	2%	0.1%	59%
WN 543 Southwest	BWI 12:06	GSP 13:47	8%	2%	0.1%	no record
WN 4437 Southwest Flight history →	BWI 20:00	GSP 21:40	20%	3%	0.2%	57%
WN 2468 Southwest	BWI 20:01	GSP 21:43	21%	3%	0.2%	no record

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