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

Fri, Oct 9: WN 715 at 06:30 is the safest bet, 3% chance of being 15+ min late; the others run 8–37%.

Safest bet that day WN 715 BOI 06:30 → SMF 06:55 · 3% chance 15+ min late · usually 95% on time Riskiest WN 717 BOI 19:20 → SMF 19:45 · 37% chance 15+ min late · usually 70% 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 715 Southwest Flight history →	BOI 06:30	SMF 06:55	3%	1%	0.5%	95%
WN 716 Southwest Flight history →	BOI 11:10	SMF 11:40	8%	2%	0.5%	91%
WN 717 Southwest Flight history →	BOI 19:20	SMF 19:45	37%	7%	0.5%	70%
AS 2156 Alaska flown by Horizon no forecast: 12-month record	BOI 07:04	SMF 07:34	6%	3%	1.3%	94%

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