Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 8 nonstops

Fri, Oct 9: WN 1660 at 07:45 is the safest bet, 6% chance of being 15+ min late; evening flights run 22–34%.

Safest bet that day WN 1660 DEN 07:45 → ONT 09:05 · 6% chance 15+ min late · usually 84% on time Riskiest WN 2949 DEN 18:40 → ONT 20:00 · 34% chance 15+ min late · usually 40% on time

Every nonstop on Fri, Oct 9

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.


WN 1660 Southwest Flight history →	DEN 07:45	ONT 09:05	6%	1%	0.5%	84%
UA 430 United Flight history →	DEN 11:25	ONT 12:47	13%	4%	0.6%	88%
F9 2907 Frontier Flight history →	DEN 08:45	ONT 10:04	15%	4%	0.6%	91%
WN 4080 Southwest Flight history →	DEN 10:55	ONT 12:10	17%	3%	0.5%	65%
UA 2028 United Flight history →	DEN 19:20	ONT 20:42	22%	7%	0.6%	75%
F9 1261 Frontier Flight history →	DEN 22:29	ONT 23:50	27%	8%	0.6%	81%
WN 1663 Southwest Flight history →	DEN 21:15	ONT 22:40	28%	7%	0.6%	35%
WN 2949 Southwest Flight history →	DEN 18:40	ONT 20:00	34%	7%	0.6%	40%

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 Fri, Oct 9 (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