Monday, October 5 · our forecast odds · issued Mon 1:00 AM ET · 20 nonstops

Today: WN 3909 at 05:35 is the safest bet, 4% chance of being 15+ min late; evening flights run 15–23%.

Safest bet today WN 3909 SMF 05:35 → DEN 09:01 · 4% chance 15+ min late Riskiest WN 1001 SMF 16:00 → DEN 19:20 · 23% chance 15+ min late · usually 64% on time

Against a calm day 14% average chance a nonstop arrives 15+ min late; 10% 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 3909 Southwest	SMF 05:35	DEN 09:01	4%	1%	0.2%	no record
WN 3773 Southwest Flight history →	SMF 05:55	DEN 09:15	4%	1%	0.2%	100%
UA 1889 United Flight history →	SMF 05:00	DEN 08:22	5%	2%	0.2%	97%
UA 2285 United Flight history →	SMF 08:50	DEN 12:16	9%	3%	0.2%	98%
UA 1055 United	SMF 10:48	DEN 14:29	10%	3%	0.3%	no record
UA 1023 United Flight history →	SMF 10:50	DEN 14:17	11%	3%	0.3%	93%
WN 3774 Southwest Flight history →	SMF 10:15	DEN 13:35	11%	2%	0.2%	96%
WN 3837 Southwest	SMF 10:45	DEN 14:11	12%	2%	0.2%	no record
WN 3911 Southwest	SMF 12:10	DEN 15:36	13%	2%	0.4%	no record
UA 1841 United Flight history →	SMF 18:37	DEN 21:59	15%	5%	0.6%	82%
UA 1961 United Flight history →	SMF 13:00	DEN 16:26	15%	3%	0.7%	85%
WN 3775 Southwest Flight history →	SMF 12:00	DEN 15:20	15%	2%	0.4%	76%
WN 4272 Southwest	SMF 19:50	DEN 23:16	16%	3%	0.5%	no record
WN 4105 Southwest Flight history →	SMF 13:40	DEN 17:00	18%	2%	0.4%	54%
UA 566 United Flight history →	SMF 16:19	DEN 19:45	19%	5%	0.6%	87%
F9 3666 Frontier Flight history →	SMF 11:25	DEN 15:00	20%	7%	0.7%	82%
WN 670 Southwest Flight history →	SMF 17:40	DEN 21:00	20%	3%	0.4%	77%
WN 2993 Southwest Flight history →	SMF 15:00	DEN 18:20	22%	3%	0.4%	63%
WN 932 Southwest	SMF 14:40	DEN 18:06	22%	3%	0.4%	no record
WN 1001 Southwest Flight history →	SMF 16:00	DEN 19:20	23%	3%	0.4%	64%

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