Today looks rough: weather pushes the average chance of arriving 15+ min late to 52%, against 35% on a calm day. Safest: WN 3767 at 22:25, 46%.

Safest bet today WN 3767 SMF 22:25 → LAS 23:58 · 46% chance 15+ min late Riskiest WN 2317 SMF 19:00 → LAS 20:32 · 62% chance 15+ min late

Weather 52% average chance a nonstop arrives 15+ min late; 35% 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. 20 flights that already left today are not shown.


WN 3767 Southwest	SMF 22:25	LAS 23:58	46%	12%	0.2%	no record
WN 3788 Southwest Flight history →	SMF 21:15	LAS 22:50	47%	14%	0.2%	65%worse than usual
WN 3931 Southwest	SMF 21:35	LAS 23:07	50%	13%	0.3%	no record
WN 982 Southwest	SMF 19:45	LAS 21:15	56%	19%	0.2%	no record
WN 2317 Southwest	SMF 19:00	LAS 20:32	62%	24%	0.3%	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