Today: WN 4062 at 08:35 is the safest bet, 7% chance of being 15+ min late; evening flights run 16–22%.

Safest bet today WN 4062 STL 08:35 → DEN 09:57 · 7% chance 15+ min late Riskiest UA 1483 STL 16:48 → DEN 18:23 · 22% chance 15+ min late · usually 56% on time

Against a calm day 15% average chance a nonstop arrives 15+ min late; 14% 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. 4 flights that already left today are not shown.


WN 4062 Southwest	STL 08:35	DEN 09:57	7%	1%	0.2%	no record
UA 2459 United Flight history →	STL 09:06	DEN 10:30	9%	3%	0.2%	92%
WN 3910 Southwest Flight history →	STL 09:25	DEN 10:40	10%	1%	0.2%	90%
UA 1380 United Flight history →	STL 13:38	DEN 15:00	10%	4%	0.2%	86%
WN 4063 Southwest	STL 12:15	DEN 13:35	10%	2%	0.2%	no record
WN 4064 Southwest	STL 14:24	DEN 15:44	11%	3%	0.2%	no record
WN 824 Southwest Flight history →	STL 13:55	DEN 15:10	13%	3%	0.2%	60%
WN 4312 Southwest Flight history →	STL 11:30	DEN 12:40	14%	2%	0.2%	72%
WN 3912 Southwest Flight history →	STL 16:00	DEN 17:20	16%	3%	0.2%	51%
WN 2814 Southwest	STL 18:40	DEN 20:01	16%	4%	0.5%	no record
WN 3913 Southwest Flight history →	STL 18:40	DEN 20:00	18%	5%	0.5%	47%
WN 4067 Southwest	STL 21:50	DEN 23:10	18%	4%	0.5%	no record
WN 3914 Southwest Flight history →	STL 22:35	DEN 23:55	19%	4%	0.5%	60%
WN 1374 Southwest	STL 16:50	DEN 18:10	19%	4%	0.2%	no record
F9 4567 Frontier Flight history →	STL 20:08	DEN 21:44	20%	7%	0.8%	76%
UA 2323 United	STL 16:36	DEN 18:20	21%	6%	0.2%	no record
UA 1483 United Flight history →	STL 16:48	DEN 18:23	22%	5%	0.2%	56%

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