Today looks rough: weather pushes the average chance of arriving 15+ min late to 27%, against 17% on a calm day. Safest: UA 1451 at 10:24, 16%.

Safest bet today UA 1451 DEN 10:24 → JAX 16:03 · 16% chance 15+ min late · usually 85% on time Riskiest WN 2817 DEN 16:15 → JAX 21:45 · 35% chance 15+ min late

Weather 27% average chance a nonstop arrives 15+ min late; 17% 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.


UA 1451 United Flight history →	DEN 10:24	JAX 16:03	16%	4%	0.6%	85%
UA 1485 United Flight history →	DEN 16:07	JAX 21:40	24%	4%	0.6%	83%
WN 4893 Southwest	DEN 13:05	JAX 18:25	32%	5%	0.6%	no record
WN 2817 Southwest	DEN 16:15	JAX 21:45	35%	5%	0.5%	no record

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 Tue, Oct 6 (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