Monday, October 12 · typical odds for a Monday (too early for a weather forecast) · issued Tue 12:00 AM ET · 8 nonstops

Mon, Oct 12: F9 2231 at 05:55 is the safest bet, 10% chance of being 15+ min late; evening flights run 22%.

Safest bet that day F9 2231 LAS 05:55 → ONT 07:13 · 10% chance 15+ min late · usually 78% on time Riskiest F9 1923 LAS 15:43 → ONT 17:01 · 33% chance 15+ min late · usually 79% on time

Every nonstop on Mon, Oct 12

12-month record →

Ranked by the chance of arriving 15+ minutes late (typical odds: the weather this date has had in past years), 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.


F9 2231 Frontier Flight history →	LAS 05:55	ONT 07:13	10%	4%	0.9%	78%
WN 276 Southwest	LAS 09:16	ONT 10:27	11%	2%	0.6%	no record
F9 1283 Frontier Flight history →	LAS 10:49	ONT 12:11	22%	9%	0.9%	86%
WN 4570 Southwest	LAS 22:55	ONT 00:06	22%	5%	0.6%	no record
WN 2897 Southwest	LAS 21:15	ONT 22:26	22%	6%	0.6%	no record
WN 2362 Southwest	LAS 12:56	ONT 14:07	29%	5%	0.6%	no record
WN 2554 Southwest	LAS 14:39	ONT 15:50	29%	6%	0.6%	no record
F9 1923 Frontier Flight history →	LAS 15:43	ONT 17:01	33%	13%	1.0%	79%worse than usual

How these are worked out. Each flight’s odds are our forecast for that day (typical odds until the weather forecast covers it); 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 12 (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