Today: WN 1738 at 07:55 is the safest bet, 9% chance of being 15+ min late; evening flights run 20–26%.

Safest bet today WN 1738 DEN 07:55 → SMF 09:30 · 9% chance 15+ min late · usually 90% on time Riskiest WN 1741 DEN 14:25 → SMF 15:55 · 28% chance 15+ min late · usually 70% on time

Against a calm day 22% average chance a nonstop arrives 15+ min late; 20% 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 1738 Southwest Flight history →	DEN 07:55	SMF 09:30	9%	1%	0.2%	90%
UA 2149 United Flight history →	DEN 08:00	SMF 09:35	10%	2%	0.2%	94%
WN 1787 Southwest	DEN 08:35	SMF 10:07	11%	1%	0.1%	no record
UA 662 United Flight history →	DEN 13:35	SMF 15:10	18%	5%	0.5%	83%
WN 1740 Southwest Flight history →	DEN 10:20	SMF 11:55	20%	2%	0.1%	74%
UA 1208 United Flight history →	DEN 16:03	SMF 17:41	20%	5%	0.5%	82%
UA 2673 United	DEN 11:37	SMF 13:10	21%	6%	0.1%	no record
UA 1602 United Flight history →	DEN 20:30	SMF 22:12	22%	5%	0.5%	77%
F9 3665 Frontier Flight history →	DEN 09:01	SMF 10:35	22%	5%	0.6%	82%
UA 1415 United Flight history →	DEN 11:30	SMF 13:05	23%	5%	0.1%	82%
WN 1744 Southwest Flight history →	DEN 21:35	SMF 23:10	23%	6%	0.5%	33%
WN 1791 Southwest	DEN 21:06	SMF 22:39	24%	6%	0.5%	no record
UA 2132 United Flight history →	DEN 19:37	SMF 21:12	24%	6%	0.5%	74%
UA 1268 United Flight history →	DEN 20:40	SMF 22:15	25%	6%	0.5%	58%
WN 4096 Southwest Flight history →	DEN 15:50	SMF 17:25	26%	6%	0.4%	48%
WN 136 Southwest Flight history →	DEN 20:20	SMF 21:55	26%	6%	0.5%	9%
WN 1790 Southwest	DEN 18:40	SMF 20:13	26%	6%	0.5%	no record
WN 2472 Southwest	DEN 15:51	SMF 17:24	27%	6%	0.4%	no record
WN 1788 Southwest	DEN 12:15	SMF 13:48	28%	3%	0.1%	no record
WN 1741 Southwest Flight history →	DEN 14:25	SMF 15:55	28%	5%	0.4%	70%

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