Wednesday, October 7 · typical odds for a Wednesday (too early for a weather forecast) · issued Sat 12:00 PM ET · 8 nonstops

Wed, Oct 7: UA 3932 at 01:15 is the safest bet, 12% chance of being 15+ min late; evening flights run 21–33%.

Safest bet that day UA 3932 IAD 01:15 → ORD 02:16 · 12% chance 15+ min late Riskiest UA 2497 IAD 17:42 → ORD 18:50 · 33% chance 15+ min late · usually 48% on time

Every nonstop on Wed, Oct 7

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 3932 United	IAD 01:15	ORD 02:16	12%	5%	1.3%	no record
UA 1252 United Flight history →	IAD 10:31	ORD 11:53	13%	6%	0.8%	92%
UA 2691 United	IAD 05:54	ORD 06:52	13%	4%	1.1%	no record
UA 1775 United Flight history →	IAD 08:15	ORD 09:36	14%	4%	0.9%	84%
UA 2331 United Flight history →	IAD 13:15	ORD 14:29	20%	9%	0.8%	81%
UA 421 United	IAD 22:16	ORD 23:14	21%	8%	0.7%	no record
UA 2158 United	IAD 15:40	ORD 16:37	32%	13%	0.8%	no record
UA 2497 United Flight history →	IAD 17:42	ORD 18:50	33%	13%	0.7%	48%

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 Wed, Oct 7 (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