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

No clear winner: Southwest’s STL → MDW flights land within a few points of 4 in 5 on time whatever the hour.

Nonstops


Southwest	STL	MDW	1h 10m	81%	1.2%	1,704	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

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


Southwest Details →	STL 08:10 → OMA 09:25WN 4318	1h 30m Omaha	OMA 10:55 → MDW 12:20WN 1655	4h 10m	95%	88%
Southwest Details →	STL 05:45 → DEN 07:00WN 3909	3h 00m Denver	DEN 10:00 → MDW 13:25WN 755	7h 40m	100%	87%
Delta Details →	STL 06:00 → ATL 08:38DL 1524	2h 27m Atlanta	ATL 11:05 → MDW 12:05DL 2417	6h 05m	99%	84%
Southwest Details →	STL 05:40 → LGA 09:00WN 4939	1h 55m New York	LGA 10:55 → MDW 12:15WN 4573	6h 35m	98%	82%
Southwest Details →	STL 08:10 → MCI 09:15WN 3943	2h 23m Kansas City	MCI 11:38 → MDW 13:02WN 2571	4h 53m	100%	80%
Delta Details →	STL 06:30 → DTW 09:04DL 1626	3h 21m Detroit	DTW 12:25 → MDW 12:46DL 4688 · flown by Endeavor	6h 16m	97%	77%
Southwest Details →	STL 05:05 → TPA 08:25WN 3985	2h 20m Tampa	TPA 10:45 → MDW 12:25WN 4033	7h 20m	98%	77%
Southwest Details →	STL 05:05 → DAL 06:45WN 1396	3h 20m Dallas	DAL 10:05 → MDW 12:20WN 1357	7h 15m	95%	76%
Tight connection: often missed
Frontier Details →	STL 17:06 → ATL 20:07F9 4474	53m Atlanta	ATL 21:00 → MDW 22:03F9 2291	4h 58m	53%	35%
Southwest Details →	STL 21:45 → PHX 22:55WN 4360	1h 00m Phoenix	PHX 23:55 → MDW 05:10 +1WN 3298	7h 25m	31%	26%
Southwest Details →	STL 18:40 → DEN 20:00WN 3913	50m Denver	DEN 20:50 → MDW 00:15 +1WN 1615	5h 32m	35%	12%

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 20m · leaves 07:08 3%

MSP · 1h 00m · leaves 08:49 23%

Afternoon and evening

ATL · 53m · leaves 17:06 47%

DEN · 50m · leaves 18:40 65%

PHX · 1h 00m · leaves 21:45 69%

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 858 STL 05:10 → CLT Southwest WN 4529 CLT 11:35 → MDW Connection details →	3h 32m	7h 25m	99%	94%
American AA 309 STL 06:43 → DCA Southwest WN 1445 DCA 12:00 → MDW Connection details →	2h 14m	6h 17m	100%	78%
Delta DL 1597 STL 06:21 → MSP Southwest WN 4345 MSP 10:25 → MDW Connection details →	2h 28m	5h 34m	97%	78%

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