Today looks rough: weather pushes the average chance of arriving 15+ min late to 71%, against 52% on a calm day. Safest: WN 3223 at 22:47, 62%.

Safest bet today WN 3223 PHX 22:47 → ONT 00:11 · 62% chance 15+ min late Riskiest WN 2436 PHX 20:30 → ONT 21:40 · 78% chance 15+ min late · usually 62% on time

Weather 71% average chance a nonstop arrives 15+ min late; 52% 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. 9 flights that already left today are not shown.


WN 3223 Southwest	PHX 22:47	ONT 00:11	62%	11%	0.3%	no record
AA 1238 American Flight history →	PHX 20:30	ONT 21:43	68%	24%	0.5%	71%worse than usual
WN 4712 Southwest	PHX 20:47	ONT 22:11	75%	17%	0.3%	no record
WN 2436 Southwest Flight history →	PHX 20:30	ONT 21:40	78%	18%	0.3%	62%worse than usual

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 Sun, Oct 4 (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