Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 7 nonstops

Fri, Oct 9: WN 4981 at 05:45 is the safest bet, 3% chance of being 15+ min late; evening flights run 12–27%.

Safest bet that day WN 4981 SLC 05:45 → SMF 06:25 · 3% chance 15+ min late · usually 95% on time Riskiest WN 3757 SLC 20:15 → SMF 20:55 · 27% chance 15+ min late · usually 54% 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.


WN 4981 Southwest Flight history →	SLC 05:45	SMF 06:25	3%	1%	0.5%	95%
DL 1367 Delta Flight history →	SLC 08:10	SMF 08:51	6%	2%	0.6%	93%
DL 1423 Delta Flight history →	SLC 11:35	SMF 12:16	12%	3%	0.6%	86%
DL 1582 Delta Flight history →	SLC 23:04	SMF 23:44	12%	4%	0.6%	90%
DL 1342 Delta Flight history →	SLC 15:25	SMF 16:07	14%	5%	0.6%	83%
DL 2585 Delta Flight history →	SLC 17:35	SMF 18:16	15%	5%	0.6%	84%
WN 3757 Southwest Flight history →	SLC 20:15	SMF 20:55	27%	8%	0.5%	54%

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