Today looks rough: weather pushes the average chance of arriving 15+ min late to 73%, against 44% on a calm day. Safest: WN 4556 at 22:55, 66%.

Safest bet today WN 4556 DAL 22:55 → SAN 00:03 · 66% chance 15+ min late Riskiest WN 1448 DAL 18:40 → SAN 19:43 · 78% chance 15+ min late

Weather 73% average chance a nonstop arrives 15+ min late; 44% 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 4556 Southwest	DAL 22:55	SAN 00:03	66%	14%	0.7%	no record
WN 936 Southwest	DAL 18:30	SAN 19:25	75%	26%	0.6%	no record
WN 1448 Southwest	DAL 18:40	SAN 19:43	78%	24%	0.6%	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