Today: WN 3673 at 08:25 is the safest bet, 14% chance of being 15+ min late; evening flights run 35–36%.

Safest bet today WN 3673 SAN 08:25 → SAT 13:16 · 14% chance 15+ min late Riskiest WN 3530 SAN 20:25 → SAT 01:15 · 36% chance 15+ min late · usually 29% on time

Against a calm day 25% average chance a nonstop arrives 15+ min late; 19% 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.


WN 3673 Southwest	SAN 08:25	SAT 13:16	14%	2%	0.2%	no record
WN 2499 Southwest Flight history →	SAN 09:10	SAT 14:00	16%	3%	0.2%	90%
WN 957 Southwest	SAN 19:46	SAT 00:35	35%	8%	0.7%	no record
WN 3530 Southwest Flight history →	SAN 20:25	SAT 01:15	36%	9%	0.7%	29%

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