Today: AA 4435 at 07:00 is the safest bet, 8% chance of being 15+ min late; evening flights run 16–17%.

Safest bet today AA 4435 BOS 07:00 → IND 09:45 · 8% chance 15+ min late · usually 93% on time Riskiest G4 594 BOS 11:34 → IND 14:02 · 46% chance 15+ min late · usually 88% on time

Against a calm day 16% average chance a nonstop arrives 15+ min late; 9% 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 4435 American flown by Republic Flight history →	BOS 07:00	IND 09:45	8%	3%	0.2%	93%
YX 4385 Republic	BOS 07:24	IND 10:13	9%	3%	0.2%	no record
DL 5628 Delta flown by Republic Flight history →	BOS 07:35	IND 10:16	9%	4%	0.2%	88%
AA 4636 American flown by Republic Flight history →	BOS 13:46	IND 16:29	12%	6%	0.2%	89%
DL 5627 Delta flown by Republic Flight history →	BOS 13:59	IND 16:46	13%	6%	0.2%	85%
YX 4393 Republic	BOS 12:07	IND 14:59	14%	6%	0.2%	no record
DL 5616 Delta flown by Republic Flight history →	BOS 17:45	IND 20:34	16%	7%	0.6%	77%
AA 4585 American flown by Republic Flight history →	BOS 17:51	IND 20:43	17%	8%	0.6%	67%
YX 4583 Republic	BOS 18:33	IND 21:26	17%	8%	0.6%	no record
G4 594 Allegiant Flight history →	BOS 11:34	IND 14:02	46%	12%	0.7%	88%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