Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Mon 12:00 PM ET · connections flying that day

Fri, Oct 9: Southwest via Phoenix, leaving 06:20, is the safest bet: 85% chance of reaching Ontario on time.

Nonstops that day

All 1 nonstop →


WN 4391 Southwest Flight history →	HOU 07:45	ONT 08:55	8%	2%	2.4%	77%

Best connections that day, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Ontario on time, from each leg’s forecast for the day. Total trip = scheduled departure to arrival (Ontario is 2 h behind Houston). Layovers up to 4 hours. Pick a connection for its 12-month details.


Southwest Details →	HOU 05:30 → LAS 06:30WN 3671	2h 35m Las Vegas	LAS 09:05 → ONT 10:10WN 4179	6h 40m	100%	86%
Southwest Details →	HOU 06:20 → PHX 06:55WN 2062	55m Phoenix	PHX 07:50 → ONT 09:05WN 759	4h 45m	94%	85%
Southwest Details →	HOU 07:30 → SJC 09:20WN 2079	1h 30m San Jose	SJC 10:50 → ONT 12:05WN 3151	6h 35m	98%	84%
Southwest Details →	HOU 06:25 → MDW 08:50WN 2039	2h 55m Chicago	MDW 11:45 → ONT 13:50WN 2846	9h 25m	100%	81%
Southwest Details →	HOU 07:35 → OAK 09:30WN 2056	1h 20m Oakland	OAK 10:50 → ONT 12:10WN 3062	6h 35m	96%	81%
Southwest Details →	HOU 05:30 → DEN 06:55WN 1970	4h 00m Denver	DEN 10:55 → ONT 12:10WN 4080	8h 40m	100%	80%
Southwest Details →	HOU 07:35 → SMF 09:25WN 2082	2h 35m Sacramento	SMF 12:00 → ONT 13:25WN 300	7h 50m	100%	79%
Southwest Details →	HOU 09:05 → BNA 11:00WN 5068	2h 55m Nashville	BNA 13:55 → ONT 16:00WN 855	8h 55m	100%	78%

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