Today looks like a normal day here: all 4 nonstops are 10–13% likely to arrive 15+ min late.

Safest bet today WN 1643 CHS 16:45 → BWI 18:31 · 10% chance 15+ min late Riskiest WN 470 CHS 16:10 → BWI 17:45 · 13% chance 15+ min late · usually 41% on time

Against a calm day 12% average chance a nonstop arrives 15+ min late; 18% 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. 4 flights that already left today are not shown.


WN 1643 Southwest	CHS 16:45	BWI 18:31	10%	4%	0.3%	no record
WN 884 Southwest	CHS 20:05	BWI 21:51	11%	4%	0.3%	no record
WN 1144 Southwest Flight history →	CHS 19:35	BWI 21:20	13%	4%	0.3%	74%
WN 470 Southwest Flight history →	CHS 16:10	BWI 17:45	13%	4%	0.2%	41%

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