Today looks rough: weather pushes the average chance of arriving 15+ min late to 59%, against 40% on a calm day. Safest: DL 5819 at 16:00, 42%.

Safest bet today DL 5819 LGA 16:00 → BOS 17:37 · 42% chance 15+ min late · usually 58% on time Riskiest DL 5746 LGA 18:59 → BOS 20:45 · 69% chance 15+ min late · usually 57% on time

Weather 59% average chance a nonstop arrives 15+ min late; 40% 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. 14 flights that already left today are not shown.


DL 5819 Delta flown by Republic Flight history →	LGA 16:00	BOS 17:37	42%	14%	0.8%	58%
YX 4502 Republic	LGA 21:19	BOS 22:34	48%	20%	1.2%	no record
DL 5839 Delta flown by Republic Flight history →	LGA 21:59	BOS 23:14	49%	16%	1.0%	78%worse than usual
DL 5751 Delta flown by Republic Flight history →	LGA 21:00	BOS 22:33	49%	27%	1.2%	68%worse than usual
DL 2801 Delta Flight history →	LGA 21:59	BOS 23:31	53%	21%	0.6%	47%
DL 1739 Delta	LGA 21:02	BOS 22:07	55%	28%	0.7%	no record
DL 5725 Delta flown by Republic Flight history →	LGA 17:00	BOS 18:40	60%	23%	0.9%	69%worse than usual
DL 5850 Delta flown by Republic Flight history →	LGA 20:00	BOS 21:39	61%	29%	1.0%	60%worse than usual
AA 4724 American flown by Republic Flight history →	LGA 17:39	BOS 19:22	63%	24%	0.8%	59%worse than usual
DL 5800 Delta flown by Republic Flight history →	LGA 20:00	BOS 21:15	63%	24%	0.9%	72%worse than usual
AA 4430 American flown by Republic Flight history →	LGA 17:40	BOS 18:36	65%	24%	0.8%	55%worse than usual
AA 4374 American flown by Republic Flight history →	LGA 17:59	BOS 19:28	67%	23%	0.8%	73%worse than usual
DL 5738 Delta flown by Republic Flight history →	LGA 18:00	BOS 19:40	67%	22%	0.9%	65%worse than usual
AA 4768 American flown by Republic Flight history →	LGA 19:12	BOS 20:27	68%	24%	1.0%	63%worse than usual
DL 5746 Delta flown by Republic Flight history →	LGA 18:59	BOS 20:45	69%	30%	1.0%	57%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 Sun, Oct 4 (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