Today: WN 3687 at 08:05 is the safest bet, 15% chance of being 15+ min late; evening flights run 20–33%.

Safest bet today WN 3687 SAN 08:05 → SLC 11:06 · 15% chance 15+ min late Riskiest WN 4810 SAN 15:45 → SLC 18:40 · 38% chance 15+ min late · usually 50% on time

Against a calm day 25% average chance a nonstop arrives 15+ min late; 19% for the same flights on a calm-weather day

Every nonstop today

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. 1 flight that already left today is not shown.


WN 3687 Southwest	SAN 08:05	SLC 11:06	15%	3%	0.2%	no record
DL 1177 Delta Flight history →	SAN 09:46	SLC 12:50	15%	4%	0.2%	93%
DL 1210 Delta Flight history →	SAN 17:01	SLC 19:59	20%	6%	0.2%	82%
DL 1252 Delta Flight history →	SAN 19:17	SLC 22:17	21%	6%	0.8%	90%worse than usual
DL 833 Delta Flight history →	SAN 19:13	SLC 22:15	23%	6%	0.8%	81%
DL 1296 Delta Flight history →	SAN 13:15	SLC 16:18	25%	5%	0.2%	87%worse than usual
OO 3118 SkyWest	SAN 08:22	SLC 11:26	26%	8%	0.2%	no record
AS 3122 Alaska flown by SkyWest Flight history →	SAN 08:55	SLC 12:09	26%	6%	0.2%	94%worse than usual
AS 3017 Alaska flown by SkyWest Flight history →	SAN 18:56	SLC 22:04	30%	10%	0.8%	73%
WN 1085 Southwest	SAN 17:01	SLC 20:02	33%	8%	0.2%	no record
AS 3488 Alaska flown by SkyWest Flight history →	SAN 15:54	SLC 19:02	35%	9%	0.3%	81%worse than usual
WN 4810 Southwest Flight history →	SAN 15:45	SLC 18:40	38%	9%	0.1%	50%

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