Today: DL 5740 at 06:00 is the safest bet, 9% chance of being 15+ min late; evening flights run 16–37%.

Safest bet today DL 5740 PHL 06:00 → BOS 07:30 · 9% chance 15+ min late · usually 92% on time Riskiest AA 3186 PHL 13:00 → BOS 14:37 · 55% chance 15+ min late

Against a calm day 30% average chance a nonstop arrives 15+ min late; 21% 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.


DL 5740 Delta flown by Republic Flight history →	PHL 06:00	BOS 07:30	9%	3%	0.8%	92%
DL 5714 Delta flown by Republic Flight history →	PHL 19:55	BOS 21:49	16%	5%	0.7%	70%
AA 2903 American	PHL 07:14	BOS 08:51	17%	6%	0.8%	no record
B6 160 JetBlue	PHL 06:01	BOS 07:27	17%	6%	0.8%	no record
AA 3225 American Flight history →	PHL 07:18	BOS 08:43	18%	6%	0.8%	89%
YX 4411 Republic	PHL 16:38	BOS 18:27	19%	6%	0.7%	no record
DL 5845 Delta flown by Republic Flight history →	PHL 09:30	BOS 10:58	20%	4%	0.8%	90%
AA 2783 American Flight history →	PHL 08:27	BOS 09:55	22%	7%	0.8%	87%
DL 5706 Delta flown by Republic Flight history →	PHL 17:35	BOS 19:07	22%	6%	0.7%	67%
AA 2780 American	PHL 08:48	BOS 10:07	28%	7%	0.9%	no record
AA 3327 American Flight history →	PHL 19:36	BOS 21:10	30%	9%	0.8%	52%
AA 2164 American	PHL 19:02	BOS 20:21	33%	10%	1.2%	no record
AA 1416 American Flight history →	PHL 10:30	BOS 12:03	33%	11%	0.7%	84%worse than usual
AA 3073 American Flight history →	PHL 14:58	BOS 16:36	33%	10%	1.0%	40%
B6 560 JetBlue Flight history →	PHL 18:44	BOS 20:09	33%	16%	0.7%	56%
AA 834 American	PHL 21:59	BOS 23:18	33%	9%	1.2%	no record
B6 1860 JetBlue Flight history →	PHL 15:53	BOS 17:18	35%	16%	0.7%	83%worse than usual
AA 3116 American Flight history →	PHL 15:20	BOS 16:47	35%	9%	0.8%	47%
AA 1874 American Flight history →	PHL 20:13	BOS 21:31	35%	9%	0.8%	72%
AA 1776 American Flight history →	PHL 17:30	BOS 18:57	37%	9%	0.8%	64%
AA 2404 American	PHL 17:30	BOS 18:49	37%	9%	0.9%	no record
DL 5805 Delta flown by Republic Flight history →	PHL 13:10	BOS 14:40	44%	14%	0.8%	72%worse than usual
B6 1160 JetBlue Flight history →	PHL 10:46	BOS 12:11	47%	14%	0.8%	85%worse than usual
AA 2882 American Flight history →	PHL 12:50	BOS 14:23	51%	19%	0.8%	80%worse than usual
AA 3186 American	PHL 13:00	BOS 14:37	55%	21%	0.8%	no record

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