Today: WN 698 at 07:10 is the safest bet, 6% chance of being 15+ min late; evening flights run 22–27%.

Safest bet today WN 698 BOI 07:10 → DEN 09:00 · 6% chance 15+ min late · usually 98% on time Riskiest UA 2395 BOI 17:46 → DEN 19:45 · 27% chance 15+ min late · usually 46% on time

Against a calm day 14% average chance a nonstop arrives 15+ min late; 10% 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.


WN 698 Southwest Flight history →	BOI 07:10	DEN 09:00	6%	2%	0.1%	98%
UA 5924 United flown by SkyWest Flight history →	BOI 05:00	DEN 07:05	7%	3%	0.2%	91%
WN 1895 Southwest	BOI 07:55	DEN 09:57	8%	2%	0.1%	no record
UA 1782 United Flight history →	BOI 06:30	DEN 08:29	8%	3%	0.2%	92%
WN 699 Southwest Flight history →	BOI 10:25	DEN 12:20	12%	3%	0.1%	91%
WN 3896 Southwest	BOI 10:41	DEN 12:44	13%	3%	0.1%	no record
UA 6041 United flown by SkyWest Flight history →	BOI 10:20	DEN 12:27	14%	6%	0.2%	91%
UA 1139 United	BOI 10:32	DEN 12:40	14%	6%	0.2%	no record
WN 4231 Southwest	BOI 15:50	DEN 17:52	15%	3%	0.5%	no record
UA 2173 United Flight history →	BOI 14:41	DEN 16:40	19%	5%	0.5%	76%
WN 700 Southwest Flight history →	BOI 16:25	DEN 18:20	22%	4%	0.4%	30%
UA 2395 United Flight history →	BOI 17:46	DEN 19:45	27%	6%	0.5%	46%

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