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 8 am and 1 time in 4 at 4 pm.

Nonstops


United	PHL	DEN	4h 20m	84%	0.7%	953	Flying now
American	PHL	DEN	4h 20m	74%	1.4%	904	Flying now
Southwest	PHL	DEN	4h 10m	71%	1.1%	879	Flying now
Frontier	PHL	DEN	4h 19m	68%	2.7%	297	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 2 h behind Philadelphia). Layovers up to 4 hours. Pick a connection for the details.


United Details →	PHL 06:10 → IAD 07:19UA 3693 · flown by Republic	2h 54m Dulles	IAD 10:13 → DEN 12:05UA 1865	7h 55m	100%	92%
United Details →	PHL 06:00 → ORD 07:30UA 660	3h 24m Chicago	ORD 10:54 → DEN 12:45UA 581	8h 45m	100%	91%
Southwest Details →	PHL 06:12 → STL 07:32WN 3227	1h 10m St Louis	STL 08:42 → DEN 10:02WN 3910	5h 50m	96%	86%
United Details →	PHL 06:15 → IAH 08:44UA 584	3h 49m Houston	IAH 12:33 → DEN 14:17UA 2168	10h 02m	100%	86%
Delta Details →	PHL 06:25 → ATL 08:32DL 1152	3h 13m Atlanta	ATL 11:45 → DEN 12:59DL 706	8h 34m	99%	84%
United Details →	PHL 08:05 → ORD 09:34UA 1811	3h 22m Chicago	ORD 12:56 → DEN 14:46UA 1150	8h 41m	99%	84%
Delta Details →	PHL 07:23 → SLC 10:06DL 2023	3h 14m Salt Lake City	SLC 13:20 → DEN 14:56DL 1623	9h 33m	98%	82%
Delta Details →	PHL 08:05 → ATL 10:12DL 1180	2h 38m Atlanta	ATL 12:50 → DEN 14:04DL 957	7h 59m	95%	82%
Tight connection: often missed
American Details →	PHL 07:39 → ORD 09:08AA 3074	52m Chicago	ORD 10:00 → DEN 11:44AA 1744	6h 05m	75%	61%
Delta Details →	PHL 16:08 → ATL 18:25DL 2131	1h 00m Atlanta	ATL 19:25 → DEN 20:44DL 746	6h 36m	70%	48%
Southwest Details →	PHL 18:55 → MDW 20:20WN 3226	1h 05m Chicago	MDW 21:25 → DEN 23:05WN 2770	6h 15m	64%	34%

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

STL · 1h 10m · leaves 06:12 4%

ORD · 1h 10m · leaves 06:00 4%

ATL · 1h 18m · leaves 06:25 6%

Afternoon and evening

IAH · 46m · leaves 13:04 25%

ATL · 1h 00m · leaves 16:08 30%

MDW · 1h 05m · leaves 18:55 36%

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.


American AA 2093 PHL 07:00 → MCO United UA 1520 MCO 12:50 → DEN Connection details →	3h 06m	9h 51m	99%	91%
American AA 2807 PHL 07:00 → TPA United UA 645 TPA 12:45 → DEN Connection details →	2h 49m	9h 47m	100%	90%
Delta DL 2023 PHL 07:23 → SLC United UA 4720 SLC 13:05 → DEN Connection details →	2h 59m	9h 28m	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