Today: UA 315 at 12:00 is the safest bet, 15% chance of being 15+ min late; evening flights run 27–28%.

Safest bet today UA 315 IAH 12:00 → PIT 15:56 · 15% chance 15+ min late · usually 85% on time Riskiest UA 1591 IAH 20:03 → PIT 23:59 · 28% chance 15+ min late · usually 76% on time

Against a calm day 24% 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.


UA 315 United Flight history →	IAH 12:00	PIT 15:56	15%	6%	0.3%	85%
UA 2757 United	IAH 17:58	PIT 21:37	27%	9%	0.2%	no record
UA 1591 United Flight history →	IAH 20:03	PIT 23:59	28%	7%	0.7%	76%

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