Today looks rough: weather pushes the average chance of arriving 15+ min late to 58%, against 37% on a calm day. Safest: DL 627 at 19:50, 50%.

Safest bet today DL 627 LAS 19:50 → SLC 22:14 · 50% chance 15+ min late Riskiest WN 4161 LAS 21:30 → SLC 23:55 · 70% chance 15+ min late · usually 77% on time

Weather 58% average chance a nonstop arrives 15+ min late; 37% 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. 12 flights that already left today are not shown.


DL 627 Delta	LAS 19:50	SLC 22:14	50%	18%	0.3%	no record
DL 1590 Delta Flight history →	LAS 19:55	SLC 22:15	50%	17%	0.3%	77%worse than usual
WN 1693 Southwest	LAS 22:42	SLC 01:07	63%	18%	0.2%	no record
WN 4161 Southwest Flight history →	LAS 21:30	SLC 23:55	70%	23%	0.2%	77%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 Sun, Oct 4 (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