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: AA 4508 at 07:00 is the safest bet, 7% chance of being 15+ min late; evening flights run 23–32%.

Safest bet that day AA 4508 LGA 07:00 → STL 08:52 · 7% chance 15+ min late · usually 94% on time Riskiest WN 4895 LGA 18:30 → STL 20:30 · 32% chance 15+ min late · usually 49% 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. Dimmed: airlines we don’t forecast yet, shown with their 12-month record if they usually fly that weekday.


AA 4508 American flown by Republic Flight history →	LGA 07:00	STL 08:52	7%	2%	0.8%	94%
WN 523 Southwest Flight history →	LGA 08:55	STL 10:45	7%	2%	0.7%	90%
AA 4509 American flown by Republic Flight history →	LGA 12:58	STL 14:50	13%	4%	0.8%	84%
WN 2473 Southwest Flight history →	LGA 12:00	STL 13:40	15%	3%	0.7%	74%
AA 4728 American flown by Republic Flight history →	LGA 18:59	STL 20:55	23%	7%	1.0%	67%
WN 2740 Southwest Flight history →	LGA 15:00	STL 17:00	24%	6%	0.8%	73%
WN 4895 Southwest Flight history →	LGA 18:30	STL 20:30	32%	11%	0.8%	49%
DL 4939 Delta flown by Endeavor no forecast: 12-month record	LGA 06:30	STL 08:08	11%	6%	2.9%	89%
DL 4922 Delta flown by Endeavor no forecast: 12-month record	LGA 10:00	STL 11:47	20%	7%	3.2%	80%
DL 4926 Delta flown by Endeavor no forecast: 12-month record	LGA 18:51	STL 20:46	30%	14%	9.5%	70%
DL 4905 Delta flown by Endeavor no forecast: 12-month record	LGA 13:59	STL 15:50	35%	15%	7.9%	65%

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