Today: UA 6027 at 20:59 is the safest bet, 13% chance of being 15+ min late; the others run 24–33%.

Safest bet today UA 6027 SFO 20:59 → BOI 23:55 · 13% chance 15+ min late · usually 63% on time Riskiest UA 5720 SFO 16:53 → BOI 19:54 · 33% chance 15+ min late · usually 74% on time

Against a calm day 24% average chance a nonstop arrives 15+ min late; 15% 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.


UA 6027 United flown by SkyWest Flight history →	SFO 20:59	BOI 23:55	13%	5%	0.5%	63%
UA 605 United	SFO 10:10	BOI 12:57	24%	4%	0.2%	no record
AS 3375 Alaska flown by SkyWest Flight history →	SFO 18:32	BOI 21:22	26%	8%	0.2%	77%
UA 5720 United flown by SkyWest Flight history →	SFO 16:53	BOI 19:54	33%	9%	0.2%	74%

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 Tue, Oct 6 (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