Today: WN 2517 at 10:10 is the safest bet, 21% chance of being 15+ min late; evening flights run 33–39%.

Safest bet today WN 2517 SAN 10:10 → BOI 13:26 · 21% chance 15+ min late Riskiest AS 3331 SAN 17:06 → BOI 20:25 · 39% chance 15+ min late · usually 79% on time

Against a calm day 33% average chance a nonstop arrives 15+ min late; 24% for the same flights on a calm-weather day

Every nonstop today

12-month record →

Ranked by the chance of arriving 15+ minutes late, 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. 1 flight that already left today is not shown.


WN 2517 Southwest	SAN 10:10	BOI 13:26	21%	3%	0.1%	no record
WN 644 Southwest Flight history →	SAN 21:05	BOI 00:25	33%	5%	0.6%	73%
WN 3627 Southwest	SAN 20:25	BOI 23:42	39%	9%	0.1%	no record
AS 3331 Alaska flown by SkyWest Flight history →	SAN 17:06	BOI 20:25	39%	8%	0.2%	79%worse than usual
AS 2341 Alaska flown by Horizon no forecast: 12-month record	SAN 10:30	BOI 13:46	25%	4%	0.0%	75%

How these are worked out. Each flight’s odds are our forecast for that day; 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 Mon, Oct 5 (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