Today: B6 778 at 20:50 is the safest bet, 33% chance of being 15+ min late; the others run 37–49%.

Safest bet today B6 778 LAS 20:50 → BOS 05:00 · 33% chance 15+ min late · usually 73% on time Riskiest B6 1178 LAS 12:12 → BOS 20:34 · 49% chance 15+ min late · usually 68% on time

Against a calm day 40% average chance a nonstop arrives 15+ min late; 33% 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. 1 flight that already left today is not shown.


B6 778 JetBlue Flight history →	LAS 20:50	BOS 05:00	33%	13%	0.7%	73%
B6 1578 JetBlue Flight history →	LAS 10:37	BOS 18:47	37%	18%	0.2%	62%
DL 430 Delta Flight history →	LAS 10:39	BOS 18:49	38%	18%	0.2%	64%
DL 1020 Delta	LAS 11:22	BOS 19:22	46%	18%	0.2%	no record
B6 1178 JetBlue Flight history →	LAS 12:12	BOS 20:34	49%	22%	0.2%	68%worse than usual

Alternatives with one stop that day

All connections →


United Details →	LAS 05:30 → DEN 08:32UA 596	1h 08m Denver	DEN 09:40 → BOS 15:44UA 1232	7h 14m	95%	78%
Delta Details →	LAS 11:44 → MSP 16:54DL 2272	1h 16m Minneapolis	MSP 18:10 → BOS 22:01DL 1502	7h 17m	91%	72%
Delta Details →	LAS 13:31 → MSP 18:42DL 2238	1h 27m Minneapolis	MSP 20:09 → BOS 23:55DL 2614	7h 24m	90%	72%

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