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 90-minute layover misses 1% of the time at 8 am and 29% of the time at 9 pm.

Nonstops


Frontier	DEN	SAN	2h 31m	81%	1.0%	704	Flying now
United	DEN	SAN	2h 25m	80%	0.4%	2,074	Flying now
Alaska	DEN	SAN	2h 40m	79%	1.4%	869	Flying now
Southwest	DEN	SAN	2h 25m	70%	0.5%	2,388	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 (San Diego is 1 h behind Denver). Layovers up to 4 hours. Pick a connection for the details.


United Details →	DEN 06:04 → LAX 07:34UA 1093	1h 26m Los Angeles	LAX 09:00 → SAN 10:08UA 4643 · flown by SkyWest	5h 04m	99%	87%
United Details →	DEN 13:26 → LAX 14:57UA 774	3h 53m Los Angeles	LAX 18:50 → SAN 19:51UA 5415 · flown by SkyWest	7h 25m	99%	84%
Delta Details →	DEN 12:45 → SLC 14:18DL 1553	2h 52m Salt Lake City	SLC 17:10 → SAN 18:06DL 1252	6h 21m	99%	82%
United Details →	DEN 05:00 → IAH 08:32UA 320	58m Houston	IAH 09:30 → SAN 10:51UA 2491	6h 51m	96%	82%
Delta Details →	DEN 07:05 → SLC 08:36DL 1581	2h 39m Salt Lake City	SLC 11:15 → SAN 12:17DL 1296	6h 12m	96%	80%
United Details →	DEN 05:15 → SFO 06:53UA 2367	1h 22m San Francisco	SFO 08:15 → SAN 09:59UA 444	5h 44m	97%	79%
Delta Details →	DEN 19:00 → SLC 20:38DL 2663	2h 17m Salt Lake City	SLC 22:55 → SAN 23:50DL 1202	5h 53m	95%	78%
United Details →	DEN 18:05 → LAX 19:40UA 2240	3h 16m Los Angeles	LAX 22:56 → SAN 23:54UA 594	6h 49m	97%	78%
Tight connection: often missed
United Details →	DEN 07:40 → SFO 09:18UA 2391	47m San Francisco	SFO 10:05 → SAN 11:51UA 2177	5h 11m	53%	35%
United Details →	DEN 09:43 → SFO 11:25UA 1506	56m San Francisco	SFO 12:21 → SAN 14:08UA 1257	5h 25m	43%	29%
American Details →	DEN 10:38 → DFW 13:40AA 1756	1h 02m Dallas-Fort Worth	DFW 14:42 → SAN 15:40AA 2485	6h 01m	71%	28%

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

IAH · 58m · leaves 05:00 4%

SEA · 1h 14m · leaves 06:30 4%

SLC · 1h 10m · leaves 10:05 8%

Afternoon and evening

MCI · 50m · leaves 14:45 55%

SEA · 47m · leaves 18:15 66%

PHX · 55m · leaves 20:05 70%

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 1731 DEN 11:45 → SLC Delta DL 1252 SLC 17:10 → SAN Connection details →	3h 45m	7h 21m	100%	84%
Southwest WN 955 DEN 13:05 → LAX Delta DL 4087 LAX 18:15 → SAN Connection details →	3h 40m	7h 11m	100%	83%
Southwest WN 4027 DEN 10:05 → SLC Alaska AS 3123 SLC 14:39 → SAN Connection details →	2h 54m	6h 41m	100%	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