Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 3 nonstops

Fri, Oct 9: WN 1580 at 07:45 is the safest bet, 7% chance of being 15+ min late; the others run 21–23%.

Safest bet that day WN 1580 DEN 07:45 → LGB 09:15 · 7% chance 15+ min late · usually 74% on time Riskiest WN 4259 DEN 13:25 → LGB 14:50 · 23% chance 15+ min late · usually 51% 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 1580 Southwest Flight history →	DEN 07:45	LGB 09:15	7%	2%	0.6%	74%
WN 1037 Southwest Flight history →	DEN 18:15	LGB 20:00	21%	6%	0.6%	56%
WN 4259 Southwest Flight history →	DEN 13:25	LGB 14:50	23%	5%	0.6%	51%

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