Today: WN 3603 at 14:25 is the safest bet, 14% chance of being 15+ min late; evening flights run 21–27%.

Safest bet today WN 3603 RSW 14:25 → BWI 17:04 · 14% chance 15+ min late Riskiest WN 4294 RSW 18:55 → BWI 21:30 · 27% chance 15+ min late · usually 56% on time

Against a calm day 20% average chance a nonstop arrives 15+ min late; 16% 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. 3 flights that already left today are not shown.


WN 3603 Southwest	RSW 14:25	BWI 17:04	14%	4%	0.5%	no record
WN 4609 Southwest Flight history →	RSW 14:05	BWI 16:30	16%	4%	0.5%	85%
WN 3604 Southwest	RSW 19:20	BWI 21:58	21%	4%	0.6%	no record
WN 4294 Southwest Flight history →	RSW 18:55	BWI 21:30	27%	4%	0.6%	56%

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