Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · 11 nonstops

Fri, Oct 9: DL 1524 at 06:00 is the safest bet, 4% chance of being 15+ min late; evening flights run 13–32%.

Safest bet that day DL 1524 STL 06:00 → ATL 08:38 · 4% chance 15+ min late · usually 96% on time Riskiest F9 4474 STL 16:57 → ATL 19:56 · 32% chance 15+ min late · usually 61% on time

Every nonstop on Fri, Oct 9

12-month record →

Ranked by the chance of arriving 15+ minutes late (typical odds: the weather this date has had in past years), 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 1524 Delta Flight history →	STL 06:00	ATL 08:38	4%	3%	0.6%	96%
DL 1536 Delta Flight history →	STL 07:08	ATL 09:45	5%	3%	0.6%	97%
DL 1571 Delta Flight history →	STL 09:24	ATL 12:02	5%	3%	0.6%	94%
WN 236 Southwest Flight history →	STL 10:00	ATL 12:35	5%	2%	0.6%	92%
DL 1400 Delta Flight history →	STL 10:51	ATL 13:25	6%	3%	0.6%	88%
DL 566 Delta Flight history →	STL 13:22	ATL 16:07	9%	4%	0.6%	86%
DL 2700 Delta Flight history →	STL 15:58	ATL 18:43	11%	4%	0.6%	87%
DL 1393 Delta Flight history →	STL 18:58	ATL 21:44	13%	4%	0.6%	83%
WN 3883 Southwest Flight history →	STL 20:05	ATL 22:45	22%	6%	0.6%	70%
WN 3882 Southwest Flight history →	STL 16:25	ATL 19:00	26%	5%	0.6%	45%
F9 4474 Frontier Flight history →	STL 16:57	ATL 19:56	32%	14%	0.9%	61%

How these are worked out. Each flight’s odds are our forecast for that day (typical odds until the weather forecast covers it); 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 Fri, Oct 9 (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