Monday, October 5 · our forecast odds · issued Sun 3:00 PM ET · 3 nonstops

Tomorrow: WN 4274 at 05:05 is the safest bet, 5% chance of being 15+ min late; the others run 6–19%.

Safest bet that day WN 4274 SMF 05:05 → DAL 10:20 · 5% chance 15+ min late · usually 83% on time Riskiest WN 3772 SMF 17:25 → DAL 22:50 · 19% chance 15+ min late · usually 51% on time

Against a calm day 10% average chance a nonstop arrives 15+ min late; 9% for the same flights on a calm-weather day

Every nonstop on Mon, Oct 5

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.


WN 4274 Southwest Flight history →	SMF 05:05	DAL 10:20	5%	1%	0.5%	83%
WN 1473 Southwest	SMF 04:52	DAL 10:11	6%	1%	0.5%	no record
WN 3772 Southwest Flight history →	SMF 17:25	DAL 22:50	19%	5%	0.5%	51%

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