Thursday, October 8 · typical odds for a Thursday (too early for a weather forecast) · issued Sun 12:00 PM ET · 5 nonstops

Thu, Oct 8: UA 1734 at 05:45 is the safest bet, 5% chance of being 15+ min late; evening flights run 28%.

Safest bet that day UA 1734 BOS 05:45 → IAD 07:23 · 5% chance 15+ min late · usually 97% on time Riskiest YX 3409 BOS 17:57 → IAD 20:18 · 28% chance 15+ min late

Every nonstop on Thu, Oct 8

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.


UA 1734 United Flight history →	BOS 05:45	IAD 07:23	5%	2%	0.8%	97%
UA 2098 United Flight history →	BOS 09:25	IAD 11:07	12%	5%	0.9%	91%
UA 721 United Flight history →	BOS 14:15	IAD 15:57	17%	8%	0.8%	78%
UA 2136 United Flight history →	BOS 19:27	IAD 21:16	28%	12%	0.7%	71%
YX 3409 Republic	BOS 17:57	IAD 20:18	28%	9%	1.4%	no record

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 Thu, Oct 8 (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