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 77% on time.

Nonstops


Delta	SEA	SAN	2h 53m	83%	1.0%	1,704	Flying now
Alaska	SEA	SAN	2h 54m	75%	1.1%	2,743	Flying now
Southwest	SEA	SAN	2h 50m	54%	0.0%	149	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

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


Delta Details →	SEA 17:30 → LAX 20:15DL 2861	2h 25m Los Angeles	LAX 22:40 → SAN 23:40DL 3746 · flown by SkyWest	6h 10m	96%	83%
Alaska Details →	SEA 08:48 → SLC 11:55AS 360	2h 44m Salt Lake City	SLC 14:39 → SAN 15:46AS 3123 · flown by SkyWest	6h 58m	100%	83%
Delta Details →	SEA 11:05 → SLC 14:11DL 1265	2h 59m Salt Lake City	SLC 17:10 → SAN 18:06DL 1252	7h 01m	99%	83%
United Details →	SEA 08:56 → DEN 12:45UA 1505	3h 10m Denver	DEN 15:55 → SAN 17:20UA 1281	8h 24m	97%	82%
Delta Details →	SEA 12:35 → LAX 15:26DL 2914	2h 49m Los Angeles	LAX 18:15 → SAN 19:16DL 4087 · flown by SkyWest	6h 41m	99%	82%
Alaska Details →	SEA 06:42 → PDX 07:37AS 2432 · flown by Horizon	3h 09m Portland	PDX 10:46 → SAN 13:27AS 1394	6h 45m	100%	82%
United Details →	SEA 05:00 → DEN 08:43UA 2601	2h 32m Denver	DEN 11:15 → SAN 12:41UA 1940	7h 41m	99%	81%
Delta Details →	SEA 05:30 → SLC 08:30DL 1128	2h 45m Salt Lake City	SLC 11:15 → SAN 12:17DL 1296	6h 47m	98%	81%
Tight connection: often missed
Alaska Details →	SEA 11:41 → OAK 13:59AS 1328	51m Oakland	OAK 14:50 → SAN 16:26AS 3311 · flown by SkyWest	4h 45m	64%	38%
United Details →	SEA 08:45 → SFO 11:03UA 2831	1h 18m San Francisco	SFO 12:21 → SAN 14:08UA 1257	5h 23m	53%	34%
United Details →	SEA 13:30 → SFO 15:48UA 737	59m San Francisco	SFO 16:47 → SAN 18:39UA 1561	5h 09m	55%	32%

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

PHX · 1h 12m · leaves 06:16 3%

SLC · 52m · leaves 07:15 7%

OAK · 1h 11m · leaves 07:12 8%

Afternoon and evening

SFO · 59m · leaves 13:30 45%

AUS · 50m · leaves 13:30 74%

DEN · 55m · leaves 14:35 90%

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 3397 SEA 07:50 → DEN United UA 1302 DEN 13:30 → SAN Connection details →	2h 05m	7h 05m	98%	85%
Alaska AS 1300 SEA 15:59 → LAX Delta DL 3746 LAX 22:40 → SAN Connection details →	3h 56m	7h 41m	99%	84%
Delta DL 2914 SEA 12:35 → LAX United UA 5415 LAX 18:50 → SAN Connection details →	3h 24m	7h 16m	99%	83%

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