Sunday, October 11 · typical odds for a Sunday (too early for a weather forecast) · issued Mon 12:00 AM ET · 7 nonstops

Sun, Oct 11: WN 3839 at 06:00 is the safest bet, 4% chance of being 15+ min late; evening flights run 21–38%.

Safest bet that day WN 3839 SLC 06:00 → SMF 06:50 · 4% chance 15+ min late Riskiest WN 3791 SLC 21:05 → SMF 21:56 · 38% chance 15+ min late

Every nonstop on Sun, Oct 11

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 3839 Southwest	SLC 06:00	SMF 06:50	4%	1%	0.6%	no record
DL 1367 Delta Flight history →	SLC 08:10	SMF 08:51	10%	3%	0.7%	93%
DL 1423 Delta Flight history →	SLC 11:35	SMF 12:16	17%	4%	0.7%	86%
DL 1582 Delta Flight history →	SLC 23:04	SMF 23:44	21%	7%	1.0%	90%worse than usual
DL 1342 Delta Flight history →	SLC 15:25	SMF 16:07	26%	8%	0.9%	83%
DL 2585 Delta Flight history →	SLC 17:35	SMF 18:16	31%	9%	1.3%	84%worse than usual
WN 3791 Southwest	SLC 21:05	SMF 21:56	38%	11%	1.4%	no record

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 Sun, Oct 11 (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