Sunday, October 11 · typical odds for a Sunday (too early for a weather forecast) · issued Mon 12:00 AM ET · 5 nonstops

Sun, Oct 11: WN 1437 at 06:15 is the safest bet, 4% chance of being 15+ min late; the others run 12–33%.

Safest bet that day WN 1437 BOI 06:15 → SMF 06:59 · 4% chance 15+ min late Riskiest WN 656 BOI 20:10 → SMF 20:54 · 33% chance 15+ min late

Every nonstop on Sun, Oct 11

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 1437 Southwest	BOI 06:15	SMF 06:59	4%	1%	0.5%	no record
WN 5119 Southwest	BOI 10:15	SMF 10:59	12%	3%	0.5%	no record
WN 663 Southwest	BOI 14:45	SMF 15:29	25%	6%	0.5%	no record
WN 656 Southwest	BOI 20:10	SMF 20:54	33%	8%	0.5%	no record
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 Sun, Oct 11 (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