Today: UA 4730 at 07:00 is the safest bet, 6% chance of being 15+ min late; the others run 7–24%.

Safest bet today UA 4730 BOI 07:00 → LAX 08:33 · 6% chance 15+ min late · usually 91% on time Riskiest DL 3701 BOI 16:00 → LAX 17:23 · 24% chance 15+ min late · usually 88% on time

Against a calm day 12% average chance a nonstop arrives 15+ min late; 7% 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.


UA 4730 United flown by SkyWest Flight history →	BOI 07:00	LAX 08:33	6%	3%	0.2%	91%
DL 3725 Delta flown by SkyWest Flight history →	BOI 07:00	LAX 08:20	7%	3%	0.2%	96%
AS 3480 Alaska flown by SkyWest Flight history →	BOI 08:03	LAX 09:30	8%	4%	0.2%	95%
OO 3009 SkyWest	BOI 07:38	LAX 08:18	16%	4%	0.2%	no record
DL 3701 Delta flown by SkyWest Flight history →	BOI 16:00	LAX 17:23	24%	5%	0.2%	88%worse than usual
AS 2180 Alaska flown by Horizon no forecast: 12-month record	BOI 18:51	LAX 20:10	0%	0%	0.0%	100%

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