Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Mon 12:00 PM ET · 5 nonstops

Fri, Oct 9: WN 543 at 08:20 is the safest bet, 6% chance of being 15+ min late; evening flights run 16–23%.

Safest bet that day WN 543 SLC 08:20 → LGB 09:30 · 6% chance 15+ min late · usually 97% on time Riskiest WN 4983 SLC 19:20 → LGB 20:15 · 23% chance 15+ min late · usually 54% 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 543 Southwest Flight history →	SLC 08:20	LGB 09:30	6%	2%	0.5%	97%
DL 3793 Delta flown by SkyWest Flight history →	SLC 15:05	LGB 16:06	11%	4%	0.5%	94%
DL 1116 Delta Flight history →	SLC 11:05	LGB 11:59	12%	5%	0.7%	90%
DL 3124 Delta Flight history →	SLC 20:40	LGB 21:32	16%	5%	0.8%	83%
WN 4983 Southwest Flight history →	SLC 19:20	LGB 20:15	23%	7%	0.5%	54%

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