Today: DL 2479 at 10:20 is the safest bet, 20% chance of being 15+ min late; the others run 28–33%.

Safest bet today DL 2479 ATL 10:20 → PWM 13:00 · 20% chance 15+ min late · usually 87% on time Riskiest DL 2138 ATL 20:35 → PWM 23:14 · 33% chance 15+ min late · usually 69% on time

Against a calm day 27% average chance a nonstop arrives 15+ min late; 19% 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 2479 Delta Flight history →	ATL 10:20	PWM 13:00	20%	4%	0.4%	87%
DL 488 Delta Flight history →	ATL 15:17	PWM 17:54	28%	5%	0.9%	59%
DL 2138 Delta Flight history →	ATL 20:35	PWM 23:14	33%	5%	0.9%	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