Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sat 8:00 PM ET · 4 nonstops

Fri, Oct 9: WN 4421 at 06:00 is the safest bet, 2% chance of being 15+ min late; the others run 13–31%.

Safest bet that day WN 4421 OAK 06:00 → ONT 07:25 · 2% chance 15+ min late · usually 98% on time Riskiest WN 271 OAK 19:00 → ONT 20:20 · 31% chance 15+ min late · usually 62% on time

Every nonstop on Fri, Oct 9

12-month record →

Ranked by the chance of arriving 15+ minutes late (typical odds: the weather this date has had in past years), 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 4421 Southwest Flight history →	OAK 06:00	ONT 07:25	2%	1%	0.6%	98%
WN 3062 Southwest Flight history →	OAK 10:50	ONT 12:10	13%	3%	0.5%	96%
WN 381 Southwest Flight history →	OAK 15:15	ONT 16:35	25%	7%	0.5%	69%
WN 271 Southwest Flight history →	OAK 19:00	ONT 20:20	31%	11%	0.6%	62%

How these are worked out. Each flight’s odds are our forecast for that day (typical odds until the weather forecast covers it); 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 Fri, Oct 9 (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