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

Connect in the morning. The same one-hour layover misses 6% of the time at 9 am and 1 time in 3 at 3 pm.

Nonstops


United	SAN	DEN	2h 32m	87%	0.7%	2,074	Flying now
Frontier	SAN	DEN	2h 36m	83%	1.4%	705	Flying now
Alaska	SAN	DEN	2h 33m	81%	1.5%	868	Flying now
Southwest	SAN	DEN	2h 25m	73%	0.8%	2,386	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Denver on time. Total trip = scheduled departure to arrival, layover included (Denver is 1 h ahead of San Diego). Layovers up to 4 hours. Pick a connection for the details.


Southwest Details →	SAN 07:05 → RNO 08:45WN 1283	1h 45m Reno	RNO 10:30 → DEN 13:40WN 3716	5h 35m	100%	96%
Southwest Details →	SAN 06:45 → SMF 08:35WN 3544	1h 40m Sacramento	SMF 10:15 → DEN 13:35WN 3774	5h 50m	98%	94%
United Details →	SAN 22:25 → ORD 04:36UA 1457	1h 24m Chicago	ORD 06:00 → DEN 07:42 +1UA 2806	8h 17m	97%	92%
United Details →	SAN 06:20 → LAX 07:21UA 1006	3h 34m Los Angeles	LAX 10:55 → DEN 14:27UA 2061	7h 07m	99%	89%
United Details →	SAN 13:39 → SFO 15:19UA 1763	3h 37m San Francisco	SFO 18:56 → DEN 22:44UA 2436	8h 05m	98%	87%
United Details →	SAN 16:09 → SFO 17:49UA 2117	3h 11m San Francisco	SFO 21:00 → DEN 00:47 +1UA 301	7h 38m	98%	84%
Delta Details →	SAN 06:15 → SLC 09:22DL 1117	3h 58m Salt Lake City	SLC 13:20 → DEN 14:56DL 1623	7h 41m	99%	83%
Southwest Details →	SAN 08:00 → PHX 09:20WN 3524	1h 40m Phoenix	PHX 11:00 → DEN 13:45WN 3262	4h 45m	100%	81%
Tight connection: often missed
United Details →	SAN 13:39 → SFO 15:19UA 1763	51m San Francisco	SFO 16:10 → DEN 20:01UA 1430	5h 22m	68%	54%
United Details →	SAN 11:58 → IAH 17:25UA 2237	54m Houston	IAH 18:19 → DEN 20:14UA 1654	7h 16m	74%	48%
American Details →	SAN 12:20 → DFW 17:40AA 1467	50m Dallas-Fort Worth	DFW 18:30 → DEN 19:41AA 2235	6h 21m	72%	33%

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

SEA · 1h 18m · leaves 07:18 6%

SLC · 53m · leaves 06:15 6%

LAX · 48m · leaves 10:49 17%

Afternoon and evening

PHX · 1h 00m · leaves 14:45 55%

DFW · 56m · leaves 16:32 60%

SEA · 46m · leaves 15:16 63%

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.


Delta DL 3743 SAN 06:15 → LAX United UA 2061 LAX 10:55 → DEN Connection details →	3h 21m	7h 12m	99%	90%
Delta DL 1117 SAN 06:15 → SLC United UA 4720 SLC 13:05 → DEN Connection details →	3h 43m	7h 36m	99%	90%
Southwest WN 3544 SAN 06:45 → SMF United UA 1023 SMF 10:50 → DEN Connection details →	2h 15m	6h 32m	97%	88%

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