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

Fri, Oct 9: WN 3858 at 06:45 is the safest bet, 2% chance of being 15+ min late; evening flights run 23–26%.

Safest bet that day WN 3858 SNA 06:45 → SJC 08:15 · 2% chance 15+ min late · usually 100% on time Riskiest WN 342 SNA 18:25 → SJC 19:40 · 26% chance 15+ min late · usually 74% 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 3858 Southwest Flight history →	SNA 06:45	SJC 08:15	2%	1%	0.7%	100%
WN 3859 Southwest Flight history →	SNA 08:10	SJC 09:30	3%	1%	0.7%	98%
WN 3860 Southwest Flight history →	SNA 09:55	SJC 11:10	7%	2%	0.7%	90%
WN 3861 Southwest Flight history →	SNA 12:00	SJC 13:25	10%	4%	0.7%	91%
WN 3863 Southwest Flight history →	SNA 15:00	SJC 16:20	16%	4%	0.7%	90%
WN 3862 Southwest Flight history →	SNA 13:30	SJC 14:50	18%	4%	0.7%	62%
WN 3864 Southwest Flight history →	SNA 17:00	SJC 18:20	23%	6%	0.7%	53%
WN 4936 Southwest Flight history →	SNA 19:55	SJC 21:10	24%	6%	0.7%	64%
WN 342 Southwest Flight history →	SNA 18:25	SJC 19:40	26%	6%	0.7%	74%

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