Today looks rough: weather pushes the average chance of arriving 15+ min late to 36%, against 19% on a calm day. Safest: WN 4005 at 15:26, 31%.

Safest bet today WN 4005 SJC 15:26 → LGB 16:53 · 31% chance 15+ min late Riskiest WN 4907 SJC 18:55 → LGB 20:15 · 42% chance 15+ min late · usually 79% on time

Weather 36% average chance a nonstop arrives 15+ min late; 19% 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. 3 flights that already left today are not shown.


WN 4005 Southwest	SJC 15:26	LGB 16:53	31%	11%	0.2%	no record
WN 3684 Southwest Flight history →	SJC 15:00	LGB 16:15	33%	10%	0.1%	64%
WN 3823 Southwest	SJC 19:46	LGB 21:13	37%	11%	0.1%	no record
WN 4907 Southwest Flight history →	SJC 18:55	LGB 20:15	42%	13%	0.2%	79%worse than usual

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