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: AA 4181 at 06:22 is the safest bet, 11% chance of being 15+ min late; the others run 27%.

Safest bet that day AA 4181 BHM 06:22 → ORD 08:49 · 11% chance 15+ min late · usually 86% on time Riskiest AA 3971 BHM 15:37 → ORD 18:00 · 27% chance 15+ min late · usually 79% 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.


AA 4181 American flown by Envoy Flight history →	BHM 06:22	ORD 08:49	11%	4%	1.0%	86%
AA 3971 American flown by Envoy Flight history →	BHM 15:37	ORD 18:00	27%	7%	1.0%	79%
UA 4449 United flown by GoJet no forecast: 12-month record	BHM 07:18	ORD 09:41	13%	4%	1.9%	87%
UA 4168 United flown by GoJet no forecast: 12-month record	BHM 13:22	ORD 15:45	35%	9%	2.7%	65%

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