Today: WN 4386 at 08:50 is the safest bet, 10% chance of being 15+ min late; evening flights run 21–34%.

Safest bet today WN 4386 DEN 08:50 → COS 09:38 · 10% chance 15+ min late Riskiest OO 5244 DEN 20:32 → COS 21:21 · 34% chance 15+ min late

Against a calm day 26% average chance a nonstop arrives 15+ min late; 23% 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 4386 Southwest	DEN 08:50	COS 09:38	10%	1%	0.1%	no record
UA 5246 United flown by SkyWest Flight history →	DEN 07:45	COS 08:41	13%	4%	0.4%	85%
UA 5306 United flown by SkyWest Flight history →	DEN 09:45	COS 10:46	18%	5%	0.5%	83%
UA 4745 United flown by SkyWest Flight history →	DEN 23:09	COS 23:59	21%	5%	0.6%	87%
WN 3896 Southwest	DEN 13:15	COS 14:03	22%	3%	0.4%	no record
OO 741 SkyWest	DEN 23:04	COS 23:53	22%	6%	0.6%	no record
UA 4775 United flown by SkyWest Flight history →	DEN 13:30	COS 14:27	24%	6%	0.6%	73%
WN 1228 Southwest Flight history →	DEN 13:20	COS 14:05	24%	3%	0.4%	57%
UA 5308 United flown by SkyWest Flight history →	DEN 16:55	COS 17:52	25%	8%	0.6%	66%
UA 1111 United Flight history →	DEN 11:32	COS 12:23	26%	6%	0.2%	75%
UA 5546 United flown by SkyWest Flight history →	DEN 15:35	COS 16:32	27%	6%	0.6%	81%
UA 738 United	DEN 11:29	COS 12:17	28%	5%	0.2%	no record
UA 4650 United flown by SkyWest Flight history →	DEN 21:10	COS 22:06	28%	8%	0.6%	76%
WN 3811 Southwest Flight history →	DEN 20:55	COS 21:50	28%	6%	0.5%	29%
WN 4402 Southwest	DEN 21:07	COS 21:55	30%	5%	0.5%	no record
UA 4744 United flown by SkyWest Flight history →	DEN 20:30	COS 21:26	30%	9%	0.6%	28%
UA 5861 United flown by SkyWest Flight history →	DEN 17:55	COS 18:54	31%	8%	0.6%	68%
UA 4793 United flown by SkyWest Flight history →	DEN 19:05	COS 20:01	33%	9%	0.6%	74%
UA 5669 United flown by SkyWest Flight history →	DEN 19:50	COS 20:46	33%	8%	0.6%	84%worse than usual
OO 306 SkyWest	DEN 21:07	COS 21:56	33%	8%	0.6%	no record
OO 5244 SkyWest	DEN 20:32	COS 21:21	34%	8%	0.6%	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 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