Today looks like a normal day here: all 3 nonstops are 26–30% likely to arrive 15+ min late.

Safest bet today WN 958 DEN 12:10 → BUF 17:15 · 26% chance 15+ min late · usually 58% on time Riskiest UA 731 DEN 17:27 → BUF 22:36 · 30% chance 15+ min late

Against a calm day 28% average chance a nonstop arrives 15+ min late; 24% 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 958 Southwest Flight history →	DEN 12:10	BUF 17:15	26%	6%	0.1%	58%
WN 4892 Southwest	DEN 13:50	BUF 18:57	28%	10%	0.5%	no record
UA 731 United	DEN 17:27	BUF 22:36	30%	11%	0.6%	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 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