Today: UA 4745 at 23:09 is the safest bet, 24% chance of being 15+ min late; the others run 24–63%.

Safest bet today UA 4745 DEN 23:09 → COS 23:59 · 24% chance 15+ min late · usually 87% on time Riskiest WN 1265 DEN 21:10 → COS 22:05 · 63% chance 15+ min late

Against a calm day 41% average chance a nonstop arrives 15+ min late; 36% 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. 14 flights that already left today are not shown.


UA 4745 United flown by SkyWest Flight history →	DEN 23:09	COS 23:59	24%	8%	0.6%	87%worse than usual
OO 741 SkyWest	DEN 23:05	COS 23:55	24%	8%	0.6%	no record
UA 4650 United flown by SkyWest Flight history →	DEN 21:10	COS 22:06	36%	11%	0.5%	76%worse than usual
OO 306 SkyWest	DEN 21:09	COS 21:59	38%	11%	0.5%	no record
OO 5244 SkyWest	DEN 20:33	COS 21:23	42%	11%	0.5%	no record
UA 4744 United flown by SkyWest Flight history →	DEN 20:30	COS 21:26	43%	11%	0.5%	28%
WN 3854 Southwest	DEN 21:46	COS 22:35	61%	14%	0.2%	no record
WN 1265 Southwest	DEN 21:10	COS 22:05	63%	15%	0.2%	no record

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 Sun, Oct 4 (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