Today: WN 1257 at 13:02 is the safest bet, 19% chance of being 15+ min late; evening flights run 26–37%.

Safest bet today WN 1257 BUR 13:02 → SJC 14:24 · 19% chance 15+ min late Riskiest WN 840 BUR 18:35 → SJC 19:45 · 37% chance 15+ min late · usually 88% on time

Against a calm day 27% 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 1257 Southwest	BUR 13:02	SJC 14:24	19%	4%	0.6%	no record
WN 438 Southwest	BUR 13:15	SJC 14:30	21%	4%	0.6%	no record
WN 1261 Southwest	BUR 14:27	SJC 15:49	24%	4%	0.6%	no record
WN 935 Southwest	BUR 20:21	SJC 21:43	26%	8%	0.6%	no record
WN 1010 Southwest	BUR 16:47	SJC 18:09	26%	6%	0.6%	no record
WN 2842 Southwest	BUR 15:45	SJC 16:55	28%	5%	0.6%	no record
WN 3869 Southwest	BUR 19:12	SJC 20:34	30%	7%	0.6%	no record
WN 4884 Southwest Flight history →	BUR 20:20	SJC 21:30	31%	8%	0.6%	67%
WN 840 Southwest Flight history →	BUR 18:35	SJC 19:45	37%	7%	0.6%	88%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