Today looks rough: weather pushes the average chance of arriving 15+ min late to 64%, against 37% on a calm day. Safest: DL 834 at 21:19, 53%.

Safest bet today DL 834 ATL 21:19 → LAS 22:41 · 53% chance 15+ min late · usually 94% on time Riskiest DL 659 ATL 16:50 → LAS 17:28 · 75% chance 15+ min late · usually 81% on time

Weather 64% average chance a nonstop arrives 15+ min late; 37% 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. 8 flights that already left today are not shown.


DL 834 Delta Flight history →	ATL 21:19	LAS 22:41	53%	15%	0.5%	94%worse than usual
DL 825 Delta Flight history →	ATL 21:20	LAS 22:35	54%	16%	0.5%	67%worse than usual
DL 919 Delta Flight history →	ATL 18:27	LAS 19:48	60%	19%	0.4%	76%worse than usual
DL 722 Delta Flight history →	ATL 18:34	LAS 19:42	60%	19%	0.4%	63%worse than usual
DL 955 Delta Flight history →	ATL 19:54	LAS 21:01	61%	20%	0.4%	68%worse than usual
WN 2625 Southwest	ATL 20:20	LAS 21:40	67%	18%	0.3%	no record
WN 234 Southwest	ATL 19:40	LAS 20:56	68%	19%	0.3%	no record
F9 1115 Frontier Flight history →	ATL 21:19	LAS 22:45	68%	34%	1.4%	81%worse than usual
F9 3923 Frontier Flight history →	ATL 19:11	LAS 20:26	72%	36%	1.4%	59%worse than usual
DL 659 Delta Flight history →	ATL 16:50	LAS 17:28	75%	35%	0.4%	81%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