Tuesday, October 6 · our forecast odds · issued Sun 7:00 PM ET · 6 nonstops

Tue, Oct 6: UA 641 at 08:35 is the safest bet, 7% chance of being 15+ min late; evening flights run 10–18%.

Safest bet that day UA 641 IAD 08:35 → BOS 10:20 · 7% chance 15+ min late · usually 92% on time Riskiest UA 688 IAD 19:04 → BOS 20:43 · 18% chance 15+ min late · usually 63% on time

Against a calm day 12% average chance a nonstop arrives 15+ min late; 10% for the same flights on a calm-weather day

Every nonstop on Tue, Oct 6

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 641 United Flight history →	IAD 08:35	BOS 10:20	7%	2%	0.5%	92%
UA 3929 United	IAD 22:56	BOS 00:58	10%	4%	0.5%	no record
YX 3503 Republic	IAD 15:38	BOS 17:33	11%	3%	0.6%	no record
UA 755 United Flight history →	IAD 22:10	BOS 23:59	11%	3%	0.5%	81%
UA 1392 United Flight history →	IAD 12:55	BOS 14:40	14%	5%	0.5%	82%
UA 688 United Flight history →	IAD 19:04	BOS 20:43	18%	5%	0.5%	63%

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