Today looks rough: weather pushes the average chance of arriving 15+ min late to 53%, against 31% on a calm day. Safest: DL 956 at 22:59, 42%.

Safest bet today DL 956 ATL 22:59 → DEN 00:23 · 42% chance 15+ min late · usually 77% on time Riskiest F9 3599 ATL 20:30 → DEN 22:05 · 69% chance 15+ min late · usually 64% on time

Weather 53% average chance a nonstop arrives 15+ min late; 31% 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. 14 flights that already left today are not shown.


DL 956 Delta Flight history →	ATL 22:59	DEN 00:23	42%	10%	0.3%	77%worse than usual
DL 493 Delta Flight history →	ATL 15:00	DEN 16:12	46%	7%	0.3%	79%worse than usual
UA 235 United Flight history →	ATL 16:22	DEN 18:08	46%	8%	0.4%	79%worse than usual
UA 609 United	ATL 16:38	DEN 18:11	51%	10%	0.4%	no record
DL 519 Delta Flight history →	ATL 16:43	DEN 17:56	52%	11%	0.3%	69%worse than usual
WN 2991 Southwest	ATL 18:56	DEN 20:08	55%	10%	0.2%	no record
DL 746 Delta Flight history →	ATL 19:25	DEN 20:43	55%	11%	0.3%	70%worse than usual
WN 3002 Southwest Flight history →	ATL 17:15	DEN 18:35	64%	11%	0.2%	44%
F9 3599 Frontier Flight history →	ATL 20:30	DEN 22:05	69%	23%	1.3%	64%worse than usual

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 Sun, Oct 4 (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