Today: WN 1240 at 07:45 is the safest bet, 8% chance of being 15+ min late; evening flights run 22–31%.

Safest bet today WN 1240 DEN 07:45 → OAK 09:25 · 8% chance 15+ min late · usually 84% on time Riskiest WN 1843 DEN 18:50 → OAK 20:25 · 31% chance 15+ min late · usually 30% on time

Against a calm day 23% 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 1240 Southwest Flight history →	DEN 07:45	OAK 09:25	8%	1%	0.2%	84%
WN 1696 Southwest Flight history →	DEN 08:30	OAK 10:06	11%	1%	0.2%	93%
WN 1577 Southwest Flight history →	DEN 10:55	OAK 12:25	22%	2%	0.1%	66%
WN 1650 Southwest Flight history →	DEN 22:10	OAK 23:50	22%	6%	0.5%	39%
WN 986 Southwest	DEN 11:06	OAK 12:42	23%	2%	0.1%	no record
WN 3563 Southwest Flight history →	DEN 13:15	OAK 14:50	26%	3%	0.1%	65%
WN 1700 Southwest	DEN 21:00	OAK 22:37	28%	7%	0.5%	no record
WN 1698 Southwest	DEN 13:41	OAK 15:18	29%	4%	0.1%	no record
WN 1048 Southwest	DEN 18:05	OAK 19:42	30%	7%	0.6%	no record
WN 1843 Southwest Flight history →	DEN 18:50	OAK 20:25	31%	8%	0.5%	30%

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