Today: WN 702 at 12:05 is the safest bet, 13% chance of being 15+ min late; evening flights run 26–33%.

Safest bet today WN 702 BOI 12:05 → LAS 12:55 · 13% chance 15+ min late · usually 88% on time Riskiest WN 704 BOI 19:40 → LAS 20:25 · 33% chance 15+ min late · usually 45% on time

Against a calm day 23% average chance a nonstop arrives 15+ min late; 17% 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. 2 flights that already left today are not shown.


WN 702 Southwest Flight history →	BOI 12:05	LAS 12:55	13%	4%	0.1%	88%
WN 2530 Southwest	BOI 12:00	LAS 13:02	15%	4%	0.1%	no record
WN 760 Southwest	BOI 19:45	LAS 20:46	26%	6%	0.2%	no record
F9 1934 Frontier	BOI 14:43	LAS 15:56	31%	10%	1.0%	no record
WN 704 Southwest Flight history →	BOI 19:40	LAS 20:25	33%	6%	0.2%	45%
AS 2087 Alaska flown by Horizon no forecast: 12-month record	BOI 16:15	LAS 17:12	16%	8%	3.8%	84%

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