Today looks rough: weather pushes the average chance of arriving 15+ min late to 56%, against 23% on a calm day. Safest: WN 3151 at 21:00, 47%.

Safest bet today WN 3151 SNA 21:00 → SJC 22:30 · 47% chance 15+ min late Riskiest WN 3705 SNA 19:45 → SJC 21:00 · 64% chance 15+ min late

Weather 56% average chance a nonstop arrives 15+ min late; 23% 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. 11 flights that already left today are not shown.


WN 3151 Southwest	SNA 21:00	SJC 22:30	47%	9%	0.3%	no record
WN 4936 Southwest Flight history →	SNA 21:10	SJC 22:30	50%	9%	0.2%	64%worse than usual
WN 3831 Southwest	SNA 19:55	SJC 21:25	62%	10%	0.4%	no record
WN 3705 Southwest	SNA 19:45	SJC 21:00	64%	9%	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