Today looks rough: weather pushes the average chance of arriving 15+ min late to 49%, against 36% on a calm day. Safest: WN 12 at 10:45, 35%.

Safest bet today WN 12 DAL 10:45 → ATL 13:50 · 35% chance 15+ min late Riskiest WN 4008 DAL 16:30 → ATL 19:40 · 62% chance 15+ min late

Weather 49% average chance a nonstop arrives 15+ min late; 36% 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. 4 flights that already left today are not shown.


WN 12 Southwest	DAL 10:45	ATL 13:50	35%	7%	0.8%	no record
DL 1115 Delta Flight history →	DAL 12:19	ATL 15:31	38%	14%	1.2%	84%worse than usual
DL 2780 Delta Flight history →	DAL 18:39	ATL 22:00	42%	17%	1.0%	78%worse than usual
WN 2808 Southwest	DAL 21:11	ATL 00:21	46%	9%	0.8%	no record
DL 512 Delta Flight history →	DAL 15:59	ATL 19:14	49%	16%	1.0%	72%worse than usual
WN 1599 Southwest	DAL 14:05	ATL 17:16	54%	15%	0.8%	no record
WN 277 Southwest	DAL 19:05	ATL 22:10	55%	16%	0.9%	no record
WN 2121 Southwest	DAL 18:00	ATL 21:11	60%	12%	0.8%	no record
WN 4008 Southwest	DAL 16:30	ATL 19:40	62%	15%	0.8%	no record

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