Today: WN 494 at 07:50 is the safest bet, 6% chance of being 15+ min late; evening flights run 25–29%.

Safest bet today WN 494 DEN 07:50 → SJC 09:25 · 6% chance 15+ min late · usually 86% on time Riskiest WN 1777 DEN 16:50 → SJC 18:30 · 29% chance 15+ min late

Against a calm day 18% average chance a nonstop arrives 15+ min late; 18% 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.


WN 494 Southwest Flight history →	DEN 07:50	SJC 09:25	6%	1%	0.2%	86%
WN 1775 Southwest	DEN 08:30	SJC 10:08	7%	1%	0.1%	no record
WN 4387 Southwest	DEN 10:05	SJC 11:43	10%	1%	0.1%	no record
WN 2384 Southwest Flight history →	DEN 09:30	SJC 11:00	11%	1%	0.1%	73%
UA 1256 United	DEN 11:37	SJC 13:24	14%	4%	0.1%	no record
UA 2808 United Flight history →	DEN 11:45	SJC 13:24	14%	4%	0.1%	65%
WN 2743 Southwest Flight history →	DEN 12:20	SJC 13:50	20%	2%	0.1%	54%
UA 1883 United Flight history →	DEN 15:55	SJC 17:35	21%	7%	0.1%	72%
WN 1217 Southwest	DEN 18:35	SJC 20:14	25%	5%	0.5%	no record
UA 2745 United Flight history →	DEN 19:30	SJC 21:09	25%	7%	0.5%	76%
WN 3489 Southwest	DEN 20:50	SJC 22:29	26%	6%	0.6%	no record
WN 1727 Southwest Flight history →	DEN 18:55	SJC 20:25	28%	6%	0.5%	29%
WN 1777 Southwest	DEN 16:50	SJC 18:30	29%	7%	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 Mon, Oct 5 (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