Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 4 nonstops

Fri, Oct 9 looks like a normal day here: all 2 nonstops are 5–8% likely to arrive 15+ min late.

Safest bet that day UA 3668 BUF 06:15 → IAD 07:34 · 5% chance 15+ min late · usually 90% on time Riskiest UA 3430 BUF 10:34 → IAD 11:50 · 8% chance 15+ min late · usually 88% on time

Every nonstop on Fri, Oct 9

12-month record →

Ranked by the chance of arriving 15+ minutes late (typical odds: the weather this date has had in past years), 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. Dimmed: airlines we don’t forecast yet, shown with their 12-month record if they usually fly that weekday.


UA 3668 United flown by Republic Flight history →	BUF 06:15	IAD 07:34	5%	3%	0.7%	90%
UA 3430 United flown by Republic Flight history →	BUF 10:34	IAD 11:50	8%	3%	0.7%	88%
UA 4270 United flown by CommuteAir no forecast: 12-month record	BUF 19:52	IAD 21:15	18%	9%	3.9%	82%
UA 4291 United flown by CommuteAir no forecast: 12-month record	BUF 15:00	IAD 16:23	21%	10%	2.9%	79%

How these are worked out. Each flight’s odds are our forecast for that day (typical odds until the weather forecast covers it); 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 Fri, Oct 9 (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