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 BOS → MDW flights land within a few points of 73% on time whatever the hour.

Nonstops


Southwest	BOS	MDW	2h 45m	73%	1.9%	1,361	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 (Chicago is 1 h behind Boston). Layovers up to 4 hours. Pick a connection for the details.


Southwest Details →	BOS 05:50 → STL 07:45WN 752	1h 10m St Louis	STL 08:55 → MDW 10:00WN 2570	5h 10m	100%	88%
Delta Details →	BOS 05:30 → ATL 08:15DL 2242	2h 50m Atlanta	ATL 11:05 → MDW 12:05DL 2417	7h 35m	100%	85%
Southwest Details →	BOS 06:25 → DEN 08:50WN 4156	1h 10m Denver	DEN 10:00 → MDW 13:25WN 755	8h 00m	95%	83%
Southwest Details →	BOS 09:05 → BNA 10:45WN 724	2h 10m Nashville	BNA 12:55 → MDW 14:30WN 1430	6h 25m	98%	77%
Delta Details →	BOS 09:05 → ATL 11:49DL 456	3h 26m Atlanta	ATL 15:15 → MDW 16:15DL 1728	8h 10m	98%	72%
Delta Details →	BOS 15:10 → ATL 18:10DL 638	3h 05m Atlanta	ATL 21:15 → MDW 22:17DL 1076	8h 07m	96%	72%
Delta Details →	BOS 09:15 → DTW 11:25DL 1748	1h 00m Detroit	DTW 12:25 → MDW 12:46DL 4688 · flown by Endeavor	4h 31m	88%	70%
Delta Details →	BOS 05:30 → DTW 07:39DL 1019	1h 11m Detroit	DTW 08:50 → MDW 09:14DL 4684 · flown by Endeavor	4h 44m	96%	69%
Tight connection: often missed
Southwest Details →	BOS 12:55 → STL 14:45WN 4917	50m St Louis	STL 15:35 → MDW 16:40WN 556	4h 45m	40%	24%
Southwest Details →	BOS 17:45 → DAL 20:55WN 737	1h 27m Dallas	DAL 22:22 → MDW 01:00 +1WN 1359	7h 52m	60%	19%
Southwest Details →	BOS 18:50 → STL 20:55WN 754	50m St Louis	STL 21:45 → MDW 22:55WN 3957	5h 00m	27%	18%

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 05:50 0%

DTW · 1h 11m · leaves 05:30 4%

ATL · 54m · leaves 05:30 5%

Afternoon and evening

MCI · 50m · leaves 14:20 62%

STL · 50m · leaves 18:50 73%

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 418 BOS 06:05 → CLT Southwest WN 4529 CLT 11:35 → MDW Connection details →	3h 05m	7h 30m	98%	94%
Delta DL 2242 BOS 05:30 → ATL Southwest WN 224 ATL 10:00 → MDW Connection details →	1h 45m	6h 30m	96%	85%
Delta DL 5836 BOS 06:00 → LGA Southwest WN 4573 LGA 10:55 → MDW Connection details →	3h 35m	7h 15m	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