Monday, October 5 · our forecast odds · issued Sun 8:00 PM ET · 12 nonstops

Tomorrow: WN 3934 at 06:10 is the safest bet, 3% chance of being 15+ min late; evening flights run 13–25%.

Safest bet that day WN 3934 STL 06:10 → LAS 07:35 · 3% chance 15+ min late · usually 88% on time Riskiest F9 2017 STL 19:10 → LAS 20:43 · 25% chance 15+ min late · usually 76% on time

Against a calm day 12% average chance a nonstop arrives 15+ min late; 12% for the same flights on a calm-weather day

Every nonstop on Mon, Oct 5

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 3934 Southwest Flight history →	STL 06:10	LAS 07:35	3%	1%	0.1%	88%
WN 4078 Southwest	STL 05:30	LAS 07:06	3%	1%	0.1%	no record
WN 4124 Southwest	STL 07:50	LAS 09:20	5%	1%	0.1%	no record
WN 2327 Southwest Flight history →	STL 09:15	LAS 10:40	6%	2%	0.4%	77%
WN 4079 Southwest	STL 12:55	LAS 14:23	12%	3%	0.4%	no record
WN 4467 Southwest	STL 14:30	LAS 15:58	12%	3%	0.5%	no record
WN 4359 Southwest Flight history →	STL 14:20	LAS 15:45	13%	4%	0.4%	59%
WN 3936 Southwest Flight history →	STL 21:55	LAS 23:25	13%	4%	0.5%	60%
WN 2523 Southwest	STL 18:20	LAS 19:47	14%	4%	0.5%	no record
WN 3935 Southwest Flight history →	STL 19:45	LAS 21:10	16%	5%	0.5%	14%
F9 3107 Frontier Flight history →	STL 12:09	LAS 13:50	18%	10%	1.0%	79%
F9 2017 Frontier Flight history →	STL 19:10	LAS 20:43	25%	10%	1.2%	76%

Alternatives with one stop that day

All connections →


Southwest Details →	STL 05:35 → DEN 06:50WN 3909	50m Denver	DEN 07:40 → LAS 08:35WN 1559	5h 00m	94%	86%
Southwest Details →	STL 11:30 → DEN 12:40WN 4312	47m Denver	DEN 13:27 → LAS 14:22WN 1637	4h 52m	76%	58%

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