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

Fri, Oct 9: WN 4099 at 05:20 is the safest bet, 3% chance of being 15+ min late; evening flights run 27–31%.

Safest bet that day WN 4099 SMF 05:20 → PDX 06:50 · 3% chance 15+ min late · usually 95% on time Riskiest WN 3813 SMF 18:05 → PDX 19:35 · 31% chance 15+ min late · usually 46% 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 4099 Southwest Flight history →	SMF 05:20	PDX 06:50	3%	1%	0.5%	95%
WN 949 Southwest Flight history →	SMF 10:05	PDX 11:35	9%	2%	0.5%	88%
AS 621 Alaska Flight history →	SMF 11:46	PDX 13:18	16%	2%	0.7%	100%worse than usual
AS 1600 Alaska Flight history →	SMF 14:55	PDX 16:27	22%	3%	0.7%	75%
WN 422 Southwest Flight history →	SMF 14:15	PDX 15:45	22%	5%	0.5%	88%worse than usual
WN 309 Southwest Flight history →	SMF 21:50	PDX 23:25	27%	9%	0.5%	73%
WN 3813 Southwest Flight history →	SMF 18:05	PDX 19:35	31%	9%	0.5%	46%
AS 2095 Alaska flown by Horizon no forecast: 12-month record	SMF 08:13	PDX 09:47	9%	4%	1.5%	91%
AS 2335 Alaska flown by Horizon no forecast: 12-month record	SMF 19:17	PDX 20:50	33%	10%	1.9%	67%

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