tailodds FORECAST
Tickets
Any day
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 3978 at 08:10 is the safest bet, 5% chance of being 15+ min late; the others run 24%.

Nonstops that day

All 2 nonstops →
WN 3978 Southwest Flight history → STL 08:10 SAT 10:15 5% 1% 0.5% 73%
WN 3979 Southwest Flight history → STL 22:15 SAT 00:25 24% 6% 0.6% 65%

Best connections that day, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach San Antonio on time, from each leg’s forecast for the day. Total trip = scheduled departure to arrival. Layovers up to 4 hours. Pick a connection for its 12-month details.
UnitedDetails → STL 05:10 → DEN 06:32UA 362 3h 03m Denver DEN 09:35 → SAT 12:43UA 2625 7h 33m 100% 90%
SouthwestDetails → STL 05:40 → MDW 06:45WN 1008 3h 50m Chicago MDW 10:35 → SAT 13:15WN 2570 7h 35m 100% 90%
SouthwestDetails → STL 05:00 → HOU 07:05WN 3919 2h 20m Houston HOU 09:25 → SAT 10:25WN 1432 5h 25m 100% 90%
SouthwestDetails → STL 05:45 → PHX 06:55WN 3967 1h 00m Phoenix PHX 07:55 → SAT 12:05WN 4081 6h 20m 97% 90%
SouthwestDetails → STL 05:35 → DEN 06:50WN 3909 2h 30m Denver DEN 09:20 → SAT 12:25WN 3149 6h 50m 100% 89%
SouthwestDetails → STL 05:05 → DAL 06:45WN 1396 3h 05m Dallas DAL 09:50 → SAT 10:55WN 2617 5h 50m 98% 89%
DeltaDetails → STL 06:21 → MSP 07:56DL 1597 1h 04m Minneapolis MSP 09:00 → SAT 11:49DL 2667 5h 28m 96% 87%
UnitedDetails → STL 06:00 → ORD 07:30UA 2805 1h 40m Chicago ORD 09:10 → SAT 12:12UA 490 6h 12m 98% 86%
Tight connection: often missed
UnitedDetails → STL 18:30 → IAH 20:50UA 6284 · flown by Mesa 50m Houston IAH 21:40 → SAT 22:42UA 2198 4h 12m 72% 57%
SouthwestDetails → STL 19:10 → DAL 20:50WN 3597 55m Dallas DAL 21:45 → SAT 22:55WN 2231 3h 45m 65% 42%
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