Today looks like a normal day here: all 3 nonstops are 12–17% likely to arrive 15+ min late.

Safest bet today AA 3427 MIA 22:56 → BHM 23:59 · 12% chance 15+ min late · usually 85% on time Riskiest AA 3422 MIA 17:27 → BHM 18:29 · 17% chance 15+ min late · usually 82% on time

Against a calm day 15% average chance a nonstop arrives 15+ min late; 18% for the same flights on a calm-weather day

Every nonstop today

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.


AA 3427 American flown by Envoy Flight history →	MIA 22:56	BHM 23:59	12%	4%	0.2%	85%
AA 3629 American flown by Envoy Flight history →	MIA 15:50	BHM 16:55	16%	4%	0.2%	43%
AA 3422 American flown by Envoy Flight history →	MIA 17:27	BHM 18:29	17%	5%	0.2%	82%

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 Mon, Oct 5 (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