Today: YX 4412 at 13:45 is the safest bet, 16% chance of being 15+ min late; evening flights run 31–58%.

Safest bet today YX 4412 BOS 13:45 → PHL 15:30 · 16% chance 15+ min late Riskiest B6 2459 BOS 16:08 → PHL 17:54 · 58% chance 15+ min late · usually 69% on time

Against a calm day 37% average chance a nonstop arrives 15+ min late; 29% 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. 8 flights that already left today are not shown.


YX 4412 Republic	BOS 13:45	PHL 15:30	16%	6%	0.4%	no record
DL 5706 Delta flown by Republic Flight history →	BOS 15:10	PHL 16:53	21%	7%	0.6%	78%
AA 2086 American Flight history →	BOS 13:03	PHL 14:43	28%	8%	0.5%	75%
AA 2685 American	BOS 11:29	PHL 13:06	29%	7%	0.6%	no record
AA 2169 American	BOS 21:33	PHL 23:10	31%	9%	0.6%	no record
AA 3043 American Flight history →	BOS 12:38	PHL 14:16	33%	7%	0.5%	81%worse than usual
DL 5610 Delta flown by Republic Flight history →	BOS 20:25	PHL 22:07	33%	10%	0.7%	57%
DL 5714 Delta flown by Republic Flight history →	BOS 17:20	PHL 19:15	35%	10%	0.6%	66%
AA 1776 American Flight history →	BOS 15:14	PHL 16:49	38%	9%	0.6%	72%
AA 2882 American Flight history →	BOS 15:03	PHL 16:39	40%	10%	0.6%	56%
AA 2110 American	BOS 19:28	PHL 21:08	43%	11%	0.6%	no record
AA 857 American	BOS 17:07	PHL 18:46	45%	11%	0.6%	no record
AA 1147 American Flight history →	BOS 19:37	PHL 21:20	45%	14%	0.6%	46%
AA 3309 American Flight history →	BOS 17:05	PHL 18:49	45%	12%	0.6%	58%
B6 1859 JetBlue Flight history →	BOS 13:22	PHL 15:07	45%	14%	0.8%	69%worse than usual
B6 159 JetBlue Flight history →	BOS 20:27	PHL 22:13	50%	15%	0.9%	89%worse than usual
B6 2459 JetBlue Flight history →	BOS 16:08	PHL 17:54	58%	17%	1.0%	69%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