Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sat 8:00 PM ET · 7 nonstops

Fri, Oct 9: WN 4909 at 06:40 is the safest bet, 4% chance of being 15+ min late; evening flights run 26–32%.

Safest bet that day WN 4909 SMF 06:40 → BUR 07:55 · 4% chance 15+ min late · usually 100% on time Riskiest WN 3360 SMF 18:20 → BUR 19:35 · 32% chance 15+ min late · usually 76% 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 4909 Southwest Flight history →	SMF 06:40	BUR 07:55	4%	1%	1.3%	100%
WN 3764 Southwest Flight history →	SMF 09:00	BUR 10:15	7%	2%	1.3%	95%
WN 3765 Southwest Flight history →	SMF 11:10	BUR 12:30	10%	3%	1.1%	96%
WN 3767 Southwest Flight history →	SMF 14:00	BUR 15:15	23%	7%	1.0%	78%
WN 3768 Southwest Flight history →	SMF 16:00	BUR 17:15	26%	9%	0.9%	90%worse than usual
WN 1890 Southwest Flight history →	SMF 20:00	BUR 21:20	31%	12%	0.8%	88%worse than usual
WN 3360 Southwest Flight history →	SMF 18:20	BUR 19:35	32%	11%	0.9%	76%

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