Today looks rough: weather pushes the average chance of arriving 15+ min late to 39%, against 29% on a calm day. Safest: DL 1035 at 13:55, 30%.

Safest bet today DL 1035 JFK 13:55 → JAX 16:44 · 30% chance 15+ min late · usually 73% on time Riskiest B6 1677 JFK 21:42 → JAX 00:31 · 46% chance 15+ min late · usually 64% on time

Weather 39% 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. Dimmed: airlines we don’t forecast yet, shown with their 12-month record if they usually fly that weekday.


DL 1035 Delta Flight history →	JFK 13:55	JAX 16:44	30%	11%	1.2%	73%
B6 477 JetBlue	JFK 11:47	JAX 14:21	38%	14%	1.4%	no record
B6 677 JetBlue Flight history →	JFK 15:41	JAX 18:16	44%	13%	1.6%	78%worse than usual
B6 1677 JetBlue Flight history →	JFK 21:42	JAX 00:31	46%	15%	2.2%	64%worse than usual
DL 5483 Delta flown by Endeavor no forecast: 12-month record	JFK 08:45	JAX 11:28	18%	7%	3.4%	82%
DL 5123 Delta flown by Endeavor no forecast: 12-month record	JFK 19:15	JAX 22:17	26%	11%	4.9%	74%

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