Today: AA 1259 at 08:00 is the safest bet, 11% chance of being 15+ min late; evening flights run 31–35%.

Safest bet today AA 1259 BOS 08:00 → MIA 11:34 · 11% chance 15+ min late · usually 90% on time Riskiest AA 1562 BOS 17:55 → MIA 21:35 · 35% chance 15+ min late · usually 79% on time

Against a calm day 23% average chance a nonstop arrives 15+ min late; 25% 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. 4 flights that already left today are not shown.


AA 1259 American Flight history →	BOS 08:00	MIA 11:34	11%	3%	0.2%	90%
AA 815 American Flight history →	BOS 10:56	MIA 14:30	16%	4%	0.2%	88%
AA 2446 American	BOS 11:16	MIA 14:45	16%	5%	0.2%	no record
AA 1589 American Flight history →	BOS 13:42	MIA 17:22	17%	5%	0.2%	78%
AA 2247 American Flight history →	BOS 14:21	MIA 17:57	18%	6%	0.2%	76%
AA 1565 American Flight history →	BOS 15:15	MIA 18:58	24%	6%	0.2%	69%
DL 776 Delta Flight history →	BOS 15:15	MIA 18:58	26%	6%	0.2%	64%
AA 3241 American	BOS 18:29	MIA 22:03	31%	7%	0.4%	no record
AA 1184 American	BOS 17:11	MIA 20:33	33%	7%	0.2%	no record
AA 1562 American Flight history →	BOS 17:55	MIA 21:35	35%	7%	0.3%	79%worse than usual

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