Today looks rough: weather pushes the average chance of arriving 15+ min late to 36%, against 25% on a calm day. Safest: B6 619 at 06:05, 22%.

Safest bet today B6 619 BOS 06:05 → SAN 09:09 · 22% chance 15+ min late · usually 89% on time Riskiest WN 2611 BOS 10:50 → SAN 14:10 · 46% chance 15+ min late

Weather 36% average chance a nonstop arrives 15+ min late; 25% 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.


B6 619 JetBlue Flight history →	BOS 06:05	SAN 09:09	22%	4%	0.7%	89%worse than usual
B6 219 JetBlue Flight history →	BOS 08:50	SAN 11:55	29%	8%	0.7%	89%worse than usual
AS 256 Alaska Flight history →	BOS 08:28	SAN 11:43	31%	8%	0.7%	85%worse than usual
B6 319 JetBlue Flight history →	BOS 16:20	SAN 19:27	37%	8%	0.6%	79%worse than usual
AS 389 Alaska Flight history →	BOS 18:14	SAN 21:18	37%	6%	0.7%	70%
DL 571 Delta Flight history →	BOS 17:10	SAN 20:25	40%	8%	0.7%	70%
WN 749 Southwest Flight history →	BOS 16:30	SAN 19:40	46%	10%	0.7%	47%
WN 2611 Southwest	BOS 10:50	SAN 14:10	46%	11%	0.6%	no record

Alternatives with one stop that day

All connections →


Delta Details →	BOS 06:05 → SLC 09:17DL 859	1h 53m Salt Lake City	SLC 11:10 → SAN 12:08DL 1296	9h 03m	99%	83%
Southwest Details →	BOS 05:35 → STL 07:25WN 752	1h 05m St Louis	STL 08:30 → SAN 10:24WN 4403	7h 49m	100%	82%
Delta Details →	BOS 09:15 → DTW 11:24DL 1748	1h 10m Detroit	DTW 12:34 → SAN 14:19DL 761	8h 04m	91%	78%

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