Today looks rough: weather pushes the average chance of arriving 15+ min late to 45%, against 31% on a calm day. Safest: UA 493 at 13:49, 33%.

Safest bet today UA 493 DEN 13:49 → LAS 14:14 · 33% chance 15+ min late · usually 88% on time Riskiest F9 1765 DEN 18:31 → LAS 19:35 · 58% chance 15+ min late · usually 77% on time

Weather 45% average chance a nonstop arrives 15+ min late; 31% 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. 20 flights that already left today are not shown.


UA 493 United Flight history →	DEN 13:49	LAS 14:14	33%	9%	0.1%	88%worse than usual
UA 2424 United	DEN 16:10	LAS 17:22	37%	11%	0.2%	no record
UA 2338 United Flight history →	DEN 17:46	LAS 18:50	38%	12%	0.2%	64%
UA 624 United Flight history →	DEN 20:54	LAS 21:53	39%	12%	0.2%	71%worse than usual
UA 655 United Flight history →	DEN 19:05	LAS 20:08	39%	12%	0.2%	70%
UA 1953 United	DEN 19:55	LAS 20:55	39%	11%	0.2%	no record
UA 716 United Flight history →	DEN 16:00	LAS 17:03	39%	10%	0.2%	78%worse than usual
WN 1173 Southwest	DEN 22:55	LAS 23:55	43%	11%	0.2%	no record
F9 777 Frontier Flight history →	DEN 22:29	LAS 23:29	45%	17%	0.8%	74%worse than usual
WN 1638 Southwest	DEN 15:11	LAS 16:09	46%	9%	0.2%	no record
WN 1563 Southwest Flight history →	DEN 15:20	LAS 16:20	46%	9%	0.2%	52%
WN 1642 Southwest	DEN 21:01	LAS 21:59	49%	12%	0.2%	no record
WN 3167 Southwest	DEN 21:00	LAS 21:55	50%	13%	0.2%	no record
WN 1565 Southwest Flight history →	DEN 18:45	LAS 19:45	51%	12%	0.2%	36%
WN 1640 Southwest	DEN 20:09	LAS 21:07	51%	14%	0.2%	no record
WN 1639 Southwest	DEN 17:46	LAS 18:44	53%	11%	0.2%	no record
WN 3710 Southwest	DEN 17:35	LAS 18:35	54%	12%	0.2%	no record
F9 1765 Frontier Flight history →	DEN 18:31	LAS 19:35	58%	17%	0.7%	77%worse than usual

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