Today looks rough: weather pushes the average chance of arriving 15+ min late to 39%, against 21% on a calm day. Safest: WN 2578 at 19:01, 37%.

Safest bet today WN 2578 LGB 19:01 → SJC 20:25 · 37% chance 15+ min late Riskiest WN 2500 LGB 18:35 → SJC 19:45 · 42% chance 15+ min late · usually 68% on time

Weather 39% average chance a nonstop arrives 15+ min late; 21% 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 2578 Southwest	LGB 19:01	SJC 20:25	37%	10%	0.1%	no record
WN 2577 Southwest	LGB 16:41	SJC 18:05	37%	10%	0.2%	no record
WN 2500 Southwest Flight history →	LGB 18:35	SJC 19:45	42%	9%	0.2%	68%

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