Today looks rough: weather pushes the average chance of arriving 15+ min late to 45%, against 29% on a calm day. Safest: DL 488 at 21:07, 39%.

Safest bet today DL 488 BOS 21:07 → ATL 00:01 · 39% chance 15+ min late Riskiest B6 1897 BOS 21:16 → ATL 00:17 · 61% chance 15+ min late · usually 43% on time

Weather 45% 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. 13 flights that already left today are not shown.


DL 488 Delta	BOS 21:07	ATL 00:01	39%	13%	0.4%	no record
DL 973 Delta Flight history →	BOS 19:10	ATL 22:24	39%	14%	0.4%	81%worse than usual
DL 900 Delta Flight history →	BOS 20:40	ATL 23:55	42%	14%	0.4%	68%
B6 1897 JetBlue Flight history →	BOS 21:16	ATL 00:17	61%	23%	0.7%	43%

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