Friday, October 9 · typical odds for a Friday (too early for a weather forecast) · issued Sat 8:00 PM ET · connections flying that day

Fri, Oct 9: Southwest via Denver, leaving 13:10, is the safest bet: 48% chance of reaching Chicago on time; the tightest one-ticket connections make it only 43% of the time.

Nonstops that day

All 2 nonstops →


WN 3886 Southwest Flight history →	SJC 22:55	MDW 05:00	13%	4%	0.6%	94%
WN 4357 Southwest Flight history →	SJC 10:05	MDW 16:10	16%	3%	0.6%	65%

Best connections that day, one ticket

Most reliable Quickest (80%+ on time)

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


Southwest Details →	SJC 20:15 → ONT 21:35WN 3692	2h 20m Ontario	ONT 23:55 → MDW 05:40 +1WN 3153	7h 25m	98%	84%
Southwest Details →	SJC 06:25 → PHX 08:20WN 3186	1h 40m Phoenix	PHX 10:00 → MDW 15:15WN 4066	6h 50m	100%	80%
Southwest Details →	SJC 06:00 → AUS 11:30WN 2363	1h 55m Austin	AUS 13:25 → MDW 15:55WN 359	7h 55m	100%	80%
Southwest Details →	SJC 06:55 → PDX 08:40WN 3693	3h 10m Portland	PDX 11:50 → MDW 17:45WN 3202	8h 50m	100%	80%
Southwest Details →	SJC 18:50 → LAS 20:20WN 2335	3h 35m Las Vegas	LAS 23:55 → MDW 05:25 +1WN 2276	8h 35m	100%	78%
Southwest Details →	SJC 17:45 → SAN 19:10WN 3526	3h 30m San Diego	SAN 22:40 → MDW 04:40 +1WN 257	8h 55m	93%	78%
Delta Details →	SJC 06:35 → ATL 14:15DL 654	1h 00m Atlanta	ATL 15:15 → MDW 16:15DL 1728	7h 40m	94%	78%
Southwest Details →	SJC 07:40 → LAS 09:10WN 1277	2h 10m Las Vegas	LAS 11:20 → MDW 16:50WN 4506	7h 10m	100%	78%
Tight connection: often missed
Southwest Details →	SJC 14:55 → SAN 16:20WN 3701	1h 10m San Diego	SAN 17:30 → MDW 23:30WN 3448	6h 35m	73%	48%
Southwest Details →	SJC 13:10 → DEN 16:35WN 3667	1h 00m Denver	DEN 17:35 → MDW 21:00WN 1604	5h 50m	69%	48%
Southwest Details →	SJC 13:40 → LAS 15:10WN 714	55m Las Vegas	LAS 16:05 → MDW 21:45WN 2274	6h 05m	43%	30%

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