Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Mon 12:00 PM ET · 5 nonstops

Fri, Oct 9: WN 4813 at 06:00 is the safest bet, 9% chance of being 15+ min late; the others run 16–34%.

Safest bet that day WN 4813 STS 06:00 → SAN 07:40 · 9% chance 15+ min late · usually 89% on time Riskiest WN 3994 STS 17:10 → SAN 18:50 · 34% chance 15+ min late · usually 29% 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. Dimmed: airlines we don’t forecast yet, shown with their 12-month record if they usually fly that weekday.


WN 4813 Southwest Flight history →	STS 06:00	SAN 07:40	9%	2%	1.0%	89%
AS 3315 Alaska flown by SkyWest Flight history →	STS 06:26	SAN 08:15	16%	5%	3.4%	88%
AS 3047 Alaska flown by SkyWest Flight history →	STS 11:04	SAN 12:50	24%	10%	2.0%	60%
WN 3994 Southwest Flight history →	STS 17:10	SAN 18:50	34%	8%	0.9%	29%
AS 2257 Alaska flown by Horizon no forecast: 12-month record	STS 17:56	SAN 19:35	58%	18%	3.8%	42%

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