Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sun 4:00 PM ET · connections flying that day

Fri, Oct 9: WN 3971 at 10:05 is the safest bet, 7% chance of being 15+ min late; the others run 28%.

Nonstops that day

All 2 nonstops →


WN 3971 Southwest Flight history →	STL 10:05	PIT 12:40	7%	2%	0.5%	79%
WN 3972 Southwest Flight history →	STL 19:55	PIT 22:35	28%	6%	0.5%	62%

Best connections that day, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Pittsburgh on time, from each leg’s forecast for the day. Total trip = scheduled departure to arrival (Pittsburgh is 1 h ahead of St Louis). Layovers up to 4 hours. Pick a connection for its 12-month details.


Southwest Details →	STL 05:40 → MDW 06:45WN 1008	1h 00m Chicago	MDW 07:45 → PIT 10:15WN 846	3h 35m	96%	91%
Southwest Details →	STL 05:50 → BWI 08:55WN 3894	1h 45m Baltimore	BWI 10:40 → PIT 11:45WN 1052	4h 55m	99%	89%
United Details →	STL 07:20 → ORD 09:00UA 4423 · flown by GoJet	3h 40m Chicago	ORD 12:40 → PIT 15:23UA 3432 · flown by Republic	7h 03m	99%	88%
American Details →	STL 06:55 → ORD 08:23AA 1926	1h 22m Chicago	ORD 09:45 → PIT 12:31AA 4484 · flown by Republic	4h 36m	97%	88%
Delta Details →	STL 06:00 → ATL 08:38DL 1524	2h 32m Atlanta	ATL 11:10 → PIT 12:52DL 1345	5h 52m	99%	88%
Delta Details →	STL 06:30 → DTW 09:04DL 1626	1h 01m Detroit	DTW 10:05 → PIT 11:18DL 5754 · flown by Republic	3h 48m	94%	87%
Southwest Details →	STL 08:55 → MDW 10:00WN 2570	3h 35m Chicago	MDW 13:35 → PIT 16:00WN 2866	6h 05m	100%	86%
Delta Details →	STL 11:18 → MSP 12:55DL 3188	2h 30m Minneapolis	MSP 15:25 → PIT 18:40DL 3709 · flown by SkyWest	6h 22m	100%	86%
Tight connection: often missed
United Details →	STL 08:00 → ORD 09:35UA 4183 · flown by GoJet	55m Chicago	ORD 10:30 → PIT 13:14UA 2771	4h 14m	68%	58%
United Details →	STL 15:22 → ORD 17:00UA 4452 · flown by GoJet	1h 05m Chicago	ORD 18:05 → PIT 20:51UA 1946	4h 29m	66%	50%

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