Today: WN 2743 at 12:50 is the safest bet, 28% chance of being 15+ min late; evening flights run 38–49%.

Safest bet today WN 2743 DEN 12:50 → SJC 14:20 · 28% chance 15+ min late · usually 54% on time Riskiest WN 3489 DEN 21:01 → SJC 22:46 · 49% chance 15+ min late

Against a calm day 42% average chance a nonstop arrives 15+ min late; 36% 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. 6 flights that already left today are not shown.


WN 2743 Southwest Flight history →	DEN 12:50	SJC 14:20	28%	4%	0.1%	54%
WN 1386 Southwest	DEN 16:31	SJC 18:10	38%	8%	0.1%	no record
UA 1883 United Flight history →	DEN 15:55	SJC 17:35	40%	11%	0.2%	72%worse than usual
WN 1727 Southwest Flight history →	DEN 19:10	SJC 20:45	48%	13%	0.1%	29%
UA 2745 United Flight history →	DEN 19:30	SJC 21:09	48%	17%	0.2%	76%worse than usual
WN 3489 Southwest	DEN 21:01	SJC 22:46	49%	15%	0.1%	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