Today: B6 508 at 12:20 is the safest bet, 21% chance of being 15+ min late; the others run 35%.

Safest bet today B6 508 JFK 12:20 → PWM 13:45 · 21% chance 15+ min late · usually 79% on time Riskiest B6 308 JFK 22:34 → PWM 00:02 · 35% chance 15+ min late · usually 66% on time

Against a calm day 28% average chance a nonstop arrives 15+ min late; 24% 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.


B6 508 JetBlue Flight history →	JFK 12:20	PWM 13:45	21%	9%	0.3%	79%
B6 308 JetBlue Flight history →	JFK 22:34	PWM 00:02	35%	14%	0.9%	66%
DL 5411 Delta flown by Endeavor no forecast: 12-month record	JFK 22:59	PWM 00:52	19%	8%	8.4%	81%
DL 5399 Delta flown by Endeavor no forecast: 12-month record	JFK 12:45	PWM 14:19	24%	8%	1.7%	76%

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