Today: DL 4444 at 09:50 is the safest bet, 5% chance of being 15+ min late; evening flights run 15–17%.

Safest bet today DL 4444 GEG 09:50 → SLC 12:41 · 5% chance 15+ min late · usually 98% on time Riskiest DL 1503 GEG 17:10 → SLC 19:55 · 17% chance 15+ min late · usually 86% on time

Against a calm day 12% average chance a nonstop arrives 15+ min late; 10% 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.


DL 4444 Delta flown by SkyWest Flight history →	GEG 09:50	SLC 12:41	5%	3%	0.1%	98%
OO 3801 SkyWest	GEG 09:51	SLC 12:41	5%	3%	0.1%	no record
DL 1024 Delta Flight history →	GEG 19:08	SLC 21:55	15%	3%	0.6%	91%
DL 1219 Delta	GEG 19:05	SLC 21:51	15%	3%	0.6%	no record
DL 1452 Delta Flight history →	GEG 13:30	SLC 16:14	16%	3%	0.1%	86%
DL 1503 Delta Flight history →	GEG 17:10	SLC 19:55	17%	4%	0.1%	86%

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