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: Alaska via Portland, leaving 17:35, is the safest bet: 84% chance of reaching Chicago on time; the tightest one-ticket connections make it only 42% of the time.

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 Oakland). Layovers up to 4 hours. Pick a connection for its 12-month details.


Alaska Details →	OAK 17:35 → PDX 19:12AS 2304 · flown by Horizon	3h 47m Portland	PDX 22:59 → ORD 05:00 +1AS 376	9h 25m	100%	84%
Delta Details →	OAK 12:30 → SLC 15:22DL 4134 · flown by SkyWest	1h 59m Salt Lake City	SLC 17:21 → ORD 21:29DL 2413	6h 59m	98%	68%
Alaska Details →	OAK 06:22 → SEA 08:26AS 491	2h 03m Seattle	SEA 10:29 → ORD 16:44AS 429	8h 22m	100%	67%
Tight connection: often missed
Alaska Details →	OAK 14:50 → SAN 16:26AS 3311 · flown by SkyWest	57m San Diego	SAN 17:23 → ORD 23:36AS 1493	6h 46m	61%	45%
Alaska Details →	OAK 14:55 → SEA 17:00AS 1464	48m Seattle	SEA 17:48 → ORD 23:59AS 538	7h 04m	42%	31%

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