Today: DL 721 at 06:45 is the safest bet, 14% chance of being 15+ min late; the others run 30–33%.

Safest bet today DL 721 SNA 06:45 → ATL 14:19 · 14% chance 15+ min late · usually 81% on time Riskiest DL 329 SNA 14:00 → ATL 21:38 · 33% chance 15+ min late · usually 77% on time

Against a calm day 25% average chance a nonstop arrives 15+ min late; 17% 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 721 Delta Flight history →	SNA 06:45	ATL 14:19	14%	3%	0.5%	81%
DL 1521 Delta Flight history →	SNA 12:15	ATL 19:49	30%	4%	0.4%	85%worse than usual
DL 329 Delta Flight history →	SNA 14:00	ATL 21:38	33%	4%	0.4%	77%worse than usual

Alternatives with one stop that day

All connections →


Southwest Details →	SNA 07:05 → PHX 08:30WN 3887	55m Phoenix	PHX 09:25 → ATL 16:09WN 4709	6h 04m	100%	80%
United Details →	SNA 08:45 → DEN 12:09UA 489	1h 17m Denver	DEN 13:26 → ATL 18:30UA 1671	6h 45m	92%	73%
Delta Details →	SNA 10:35 → LAS 11:54DL 4078 · flown by SkyWest	1h 18m Las Vegas	LAS 13:12 → ATL 20:24DL 466	6h 49m	88%	65%

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