Today looks rough: weather pushes the average chance of arriving 15+ min late to 26%, against 15% on a calm day. Safest: DL 5619 at 18:59, 16%.

Safest bet today DL 5619 MKE 18:59 → BOS 22:26 · 16% chance 15+ min late · usually 77% on time Riskiest DL 5614 MKE 11:35 → BOS 15:05 · 32% chance 15+ min late · usually 69% on time

Weather 26% average chance a nonstop arrives 15+ min late; 15% 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 5619 Delta flown by Republic Flight history →	MKE 18:59	BOS 22:26	16%	7%	0.7%	77%
B6 2230 JetBlue Flight history →	MKE 09:35	BOS 12:48	29%	11%	0.7%	77%
DL 5614 Delta flown by Republic Flight history →	MKE 11:35	BOS 15:05	32%	20%	1.0%	69%

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