Today looks rough: weather pushes the average chance of arriving 15+ min late to 57%, against 39% on a calm day. Safest: WN 3154 at 22:35, 48%.

Safest bet today WN 3154 LAS 22:35 → SMF 00:15 · 48% chance 15+ min late Riskiest WN 2421 LAS 20:48 → SMF 22:26 · 62% chance 15+ min late

Weather 57% average chance a nonstop arrives 15+ min late; 39% 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. 18 flights that already left today are not shown.


WN 3154 Southwest	LAS 22:35	SMF 00:15	48%	10%	0.2%	no record
WN 2126 Southwest	LAS 22:38	SMF 00:16	50%	11%	0.2%	no record
WN 1435 Southwest Flight history →	LAS 20:25	SMF 22:05	58%	14%	0.2%	57%worse than usual
WN 4529 Southwest	LAS 18:43	SMF 20:21	60%	18%	0.2%	no record
WN 1914 Southwest	LAS 21:25	SMF 23:00	60%	14%	0.2%	no record
WN 2423 Southwest	LAS 21:38	SMF 23:16	60%	14%	0.2%	no record
WN 2421 Southwest	LAS 20:48	SMF 22:26	62%	15%	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 Sun, Oct 4 (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