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 3896 at 06:05 is the safest bet, 3% chance of being 15+ min late; the others run 12–18%.

Safest bet that day WN 3896 SMF 06:05 → BOI 08:44 · 3% chance 15+ min late Riskiest WN 3897 SMF 13:05 → BOI 15:43 · 18% 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 3896 Southwest	SMF 06:05	BOI 08:44	3%	1%	0.6%	no record
WN 5035 Southwest	SMF 11:25	BOI 14:03	12%	3%	0.5%	no record
WN 3956 Southwest	SMF 22:11	BOI 00:49	16%	6%	0.6%	no record
WN 3897 Southwest	SMF 13:05	BOI 15:43	18%	4%	0.5%	no record
AS 2157 Alaska flown by Horizon no forecast: 12-month record	SMF 13:10	BOI 15:35	7%	2%	1.5%	93%

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