Today: WN 203 at 13:30 is the safest bet, 16% chance of being 15+ min late; evening flights run 24–26%.

Safest bet today WN 203 BWI 13:30 → RSW 16:21 · 16% chance 15+ min late Riskiest WN 4232 BWI 20:15 → RSW 22:55 · 26% chance 15+ min late · usually 57% on time

Against a calm day 22% average chance a nonstop arrives 15+ min late; 22% 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.


WN 203 Southwest	BWI 13:30	RSW 16:21	16%	3%	0.3%	no record
WN 4569 Southwest Flight history →	BWI 15:35	RSW 18:20	20%	4%	0.3%	55%
WN 4974 Southwest	BWI 17:35	RSW 20:26	24%	4%	0.6%	no record
WN 836 Southwest	BWI 20:20	RSW 23:11	25%	4%	0.8%	no record
WN 4232 Southwest Flight history →	BWI 20:15	RSW 22:55	26%	4%	0.8%	57%

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