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 75-minute layover misses 5% of the time at 9 am and 1 time in 5 at 5 pm.

Nonstops


United	SDF	DEN	3h 07m	85%	1.0%	730	Flying now
Southwest	SDF	DEN	2h 55m	81%	1.1%	367	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 Louisville). Layovers up to 4 hours. Pick a connection for the details.


United Details →	SDF 07:15 → ORD 07:56UA 3422 · flown by Republic	2h 58m Chicago	ORD 10:54 → DEN 12:45UA 581	7h 30m	99%	95%
United Details →	SDF 06:00 → IAD 07:35UA 3438 · flown by Republic	2h 38m Dulles	IAD 10:13 → DEN 12:05UA 1865	8h 05m	99%	91%
Southwest Details →	SDF 06:15 → LAS 07:10WN 3607	1h 45m Las Vegas	LAS 08:55 → DEN 11:50WN 247	7h 35m	100%	88%
Delta Details →	SDF 08:10 → ATL 09:40DL 2299	3h 10m Atlanta	ATL 12:50 → DEN 14:04DL 957	7h 54m	98%	87%
United Details →	SDF 10:04 → ORD 10:40UA 5629 · flown by SkyWest	2h 16m Chicago	ORD 12:56 → DEN 14:46UA 1150	6h 42m	100%	87%
Delta Details →	SDF 07:50 → DTW 09:16DL 5824 · flown by Republic	3h 26m Detroit	DTW 12:42 → DEN 13:54DL 1648	8h 04m	98%	83%
American Details →	SDF 05:04 → CLT 06:41AA 5255 · flown by PSA	58m Charlotte	CLT 07:39 → DEN 09:10AA 1754	6h 06m	89%	83%
Delta Details →	SDF 07:05 → ATL 08:34DL 1610	3h 11m Atlanta	ATL 11:45 → DEN 12:59DL 706	7h 54m	97%	82%
Tight connection: often missed
American Details →	SDF 11:09 → DFW 12:30AA 3788 · flown by Envoy	47m Dallas-Fort Worth	DFW 13:17 → DEN 14:21AA 420	5h 12m	74%	54%
American Details →	SDF 18:02 → DFW 19:28AA 4152 · flown by Envoy	1h 01m Dallas-Fort Worth	DFW 20:29 → DEN 21:32AA 577	5h 30m	69%	33%
American Details →	SDF 19:50 → DFW 21:12AA 2519	1h 33m Dallas-Fort Worth	DFW 22:45 → DEN 23:55AA 662	6h 05m	61%	25%

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

ATL · 1h 16m · leaves 07:05 6%

MCO · 1h 05m · leaves 06:40 10%

CLT · 58m · leaves 05:04 11%

Afternoon and evening

CLT · 1h 08m · leaves 15:39 23%

DFW · 1h 01m · leaves 18:02 31%

MSP · 1h 13m · leaves 19:51 32%

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 3607 SDF 06:15 → LAS United UA 1315 LAS 09:37 → DEN Connection details →	2h 27m	8h 26m	100%	93%
American AA 4622 SDF 06:51 → ORD United UA 581 ORD 10:54 → DEN Connection details →	3h 16m	7h 54m	97%	92%
Southwest WN 3604 SDF 07:25 → BNA United UA 502 BNA 10:26 → DEN Connection details →	3h 11m	6h 58m	100%	90%

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