Today looks rough: weather pushes the average chance of arriving 15+ min late to 45%, against 29% on a calm day. Safest: UA 2649 at 21:05, 38%.

Safest bet today UA 2649 DEN 21:05 → ORD 00:44 · 38% chance 15+ min late · usually 71% on time Riskiest F9 3174 DEN 20:57 → ORD 00:32 · 56% chance 15+ min late · usually 68% on time

Weather 45% average chance a nonstop arrives 15+ min late; 29% 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. 28 flights that already left today are not shown.


UA 2649 United Flight history →	DEN 21:05	ORD 00:44	38%	12%	0.3%	71%
UA 377 United Flight history →	DEN 20:36	ORD 00:03	42%	14%	0.2%	80%worse than usual
F9 3174 Frontier Flight history →	DEN 20:57	ORD 00:32	56%	20%	0.7%	68%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