Itineraries flown on 20+ days in the Jun 6 – Jul 31, 2026 schedule · each leg’s record Aug 2025 – Jul 2026

No clear winner: airlines and hours on this route all land within a few points of 84% on time.

Nonstops


Delta	SJC	SEA	2h 25m	89%	0.2%	1,579	Flying now
Alaska	SJC	SEA	2h 17m	82%	1.2%	1,934	Flying now
Southwest	SJC	SEA	2h 15m	78%	0.0%	906	Flying now
American	SJC	SEA	–	100%few flights	0.0%	2	Not flying now
United	SJC	SEA	–	100%few flights	0.0%	1	Not flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Seattle on time. Total trip = scheduled departure to arrival, layover included. Layovers up to 4 hours. Pick a connection for the details.


Delta Details →	SJC 17:01 → SLC 19:57DL 1260	2h 48m Salt Lake City	SLC 22:45 → SEA 23:59DL 2998	6h 58m	99%	90%
Delta Details →	SJC 06:00 → SLC 08:55DL 1314	2h 40m Salt Lake City	SLC 11:35 → SEA 12:52DL 2995	6h 52m	98%	85%
Delta Details →	SJC 07:00 → LAX 08:27DL 1654	1h 13m Los Angeles	LAX 09:40 → SEA 12:30DL 1714	5h 34m	92%	85%
Alaska Details →	SJC 08:00 → PDX 09:44AS 679	2h 19m Portland	PDX 12:03 → SEA 13:03AS 3078 · flown by SkyWest	5h 03m	100%	85%
United Details →	SJC 08:45 → DEN 12:23UA 586	1h 37m Denver	DEN 14:00 → SEA 16:00UA 2164	7h 15m	99%	82%
Delta Details →	SJC 09:55 → LAX 11:20DL 4451 · flown by SkyWest	2h 40m Los Angeles	LAX 14:00 → SEA 16:47DL 2606	6h 52m	98%	81%
Southwest Details →	SJC 06:25 → PHX 08:20WN 3186	2h 25m Phoenix	PHX 10:45 → SEA 13:50WN 814	7h 25m	100%	81%
Delta Details →	SJC 14:59 → LAX 16:27DL 3842 · flown by SkyWest	2h 50m Los Angeles	LAX 19:17 → SEA 22:05DL 1551	7h 10m	99%	79%
Tight connection: often missed
United Details →	SJC 14:32 → DEN 18:10UA 719	1h 00m Denver	DEN 19:10 → SEA 21:10UA 360	6h 38m	63%	43%
Alaska Details →	SJC 15:15 → SAN 16:49AS 3429 · flown by SkyWest	46m San Diego	SAN 17:35 → SEA 20:35AS 417	5h 20m	53%	36%

Same layover, different day-part

How often the first flight arrives too late to connect (45 min minimum), for one-ticket layovers of 45–80 minutes.

Morning

PDX · 51m · leaves 08:00 4%

LAX · 1h 13m · leaves 07:00 8%

Afternoon and evening

SLC · 47m · leaves 17:01 14%

PDX · 1h 01m · leaves 18:37 24%

SAN · 46m · leaves 15:15 47%

Delays build through the day, so an afternoon first leg eats the layover. A short connection is fine early in the morning and a gamble later on.

Mixing airlines

One ticketMiss it and the airline rebooks you; bags go through. 45 min is enough.

Separate ticketsMiss it and you buy a new ticket. Re-check bags, clear security again: we require 90 min.


Southwest WN 3693 SJC 06:30 → PDX Delta DL 3818 PDX 11:20 → SEA Connection details →	3h 02m	6h 06m	100%	91%
Delta DL 3822 SJC 16:30 → LAX Alaska AS 495 LAX 21:12 → SEA Connection details →	3h 16m	7h 29m	98%	90%
Southwest WN 3708 SJC 08:12 → SNA Alaska AS 548 SNA 12:05 → SEA Connection details →	2h 27m	6h 42m	100%	89%

Rank all connections, any airlines →

Regional partners count as the airline that sells them: SkyWest flying Delta Connection is one Delta ticket.

How these are worked out. Makes the connection: share of the last year’s flights where the first flight arrived with at least 45 minutes to spare (90 on separate tickets). Arrives on time: first flight not cancelled × connection made × second flight not cancelled and arriving within 15 minutes. Not yet counted: the second flight also leaving late (which helps), gate-to-gate distance at the hub, and rebooking after a missed connection.

About this data: US DOT on-time records, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. Schedules (which flights and connections exist, and their times) are as of Jun 6 – Jul 31, 2026; seasonal flights outside that window aren’t ranked. Rebuilt monthly. JSON