Today: DL 3123 at 09:50 is the safest bet, 14% chance of being 15+ min late; the others run 18–24%.

Safest bet today DL 3123 SLC 09:50 → SAT 13:36 · 14% chance 15+ min late · usually 83% on time Riskiest DL 2797 SLC 20:40 → SAT 00:26 · 24% chance 15+ min late · usually 82% on time

Against a calm day 19% average chance a nonstop arrives 15+ min late; 15% 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.


DL 3123 Delta Flight history →	SLC 09:50	SAT 13:36	14%	4%	0.1%	83%
DL 2680 Delta Flight history →	SLC 13:25	SAT 17:14	18%	4%	0.1%	86%
DL 2199 Delta	SLC 13:32	SAT 17:21	18%	4%	0.1%	no record
DL 2797 Delta Flight history →	SLC 20:40	SAT 00:26	24%	4%	0.6%	82%

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