Monday, October 5 · our forecast odds · issued Sun 3:00 PM ET · 10 nonstops

Tomorrow: WN 3001 at 08:30 is the safest bet, 6% chance of being 15+ min late; evening flights run 26–31%.

Safest bet that day WN 3001 DEN 08:30 → ONT 09:54 · 6% chance 15+ min late Riskiest F9 1261 DEN 22:29 → ONT 23:50 · 31% chance 15+ min late · usually 81% on time

Against a calm day 19% average chance a nonstop arrives 15+ min late; 16% 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 3001 Southwest	DEN 08:30	ONT 09:54	6%	1%	0.4%	no record
WN 1660 Southwest Flight history →	DEN 07:45	ONT 09:05	6%	1%	0.4%	84%
UA 430 United Flight history →	DEN 11:25	ONT 12:47	12%	4%	0.5%	88%
WN 4080 Southwest Flight history →	DEN 10:55	ONT 12:10	14%	3%	0.4%	65%
WN 2947 Southwest	DEN 13:00	ONT 14:26	16%	3%	0.4%	no record
F9 2907 Frontier Flight history →	DEN 08:45	ONT 10:04	16%	5%	0.6%	91%
UA 2028 United Flight history →	DEN 19:20	ONT 20:42	26%	6%	0.5%	75%
WN 1663 Southwest Flight history →	DEN 21:15	ONT 22:40	28%	6%	0.5%	35%
WN 2949 Southwest Flight history →	DEN 18:40	ONT 20:00	30%	6%	0.5%	40%
F9 1261 Frontier Flight history →	DEN 22:29	ONT 23:50	31%	9%	0.6%	81%worse than usual

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