Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 5 nonstops

Fri, Oct 9: DL 2173 at 06:00 is the safest bet, 3% chance of being 15+ min late; the others run 4–18%.

Safest bet that day DL 2173 BOI 06:00 → SLC 07:11 · 3% chance 15+ min late · usually 91% on time Riskiest DL 2920 BOI 18:42 → SLC 19:57 · 18% chance 15+ min late · usually 81% 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.


DL 2173 Delta Flight history →	BOI 06:00	SLC 07:11	3%	3%	0.6%	91%
DL 3607 Delta flown by SkyWest Flight history →	BOI 08:25	SLC 09:44	4%	2%	0.5%	97%
DL 1754 Delta Flight history →	BOI 11:53	SLC 13:06	10%	4%	0.6%	91%
DL 1442 Delta Flight history →	BOI 13:05	SLC 14:18	12%	4%	0.6%	93%
DL 2920 Delta Flight history →	BOI 18:42	SLC 19:57	18%	5%	0.7%	81%

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