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 MDW → SEA flights land within a few points of 2 in 3 on time whatever the hour.

Nonstops (seasonal or thin)


Southwest	MDW	SEA	4h 30m	65%	0.6%	678	Flying now

Best connections, any airlines

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Seattle on time. Total trip = scheduled departure to arrival, layover included (Seattle is 2 h behind Chicago). Layovers up to 4 hours. Pick a connection for the details.


Southwest + Deltatwo ticketsDetails →	MDW 05:20 → AUS 07:50WN 2726	3h 29m Austin	AUS 11:19 → SEA 13:54DL 1684	10h 34m	100%	94%
Southwest + Deltatwo ticketsDetails →	MDW 07:10 → PHX 08:45WN 2520	3h 20m Phoenix	PHX 12:05 → SEA 15:18DL 2419	10h 08m	100%	90%
Southwest + Deltatwo ticketsDetails →	MDW 05:10 → LAX 07:25WN 4637	2h 15m Los Angeles	LAX 09:40 → SEA 12:30DL 1714	9h 24m	97%	89%
Southwest + Deltatwo ticketsDetails →	MDW 05:52 → SAN 08:00WN 3103	3h 05m San Diego	SAN 11:05 → SEA 14:21DL 2508	10h 29m	100%	89%
Southwest + Deltatwo ticketsDetails →	MDW 10:05 → PDX 12:25WN 2809	3h 01m Portland	PDX 15:26 → SEA 16:40DL 4062 · flown by SkyWest	8h 36m	100%	89%
Southwest + Deltatwo ticketsDetails →	MDW 06:30 → LAS 08:20WN 1182	2h 39m Las Vegas	LAS 10:59 → SEA 13:51DL 2922	9h 21m	98%	87%
Southwest + Deltatwo ticketsDetails →	MDW 05:20 → PHX 06:55WN 2858	2h 25m Phoenix	PHX 09:20 → SEA 12:35DL 2374	9h 15m	97%	87%
Southwest + Deltatwo ticketsDetails →	MDW 07:40 → MSP 09:10WN 1243	2h 00m Minneapolis	MSP 11:10 → SEA 12:58DL 889	7h 18m	100%	86%
Tight connection: often missed
Delta Details →	MDW 19:06 → MSP 20:51DL 4713 · flown by Endeavor	1h 17m Minneapolis	MSP 22:08 → SEA 23:58DL 505	6h 52m	70%	58%
Southwest Details →	MDW 09:55 → DEN 11:30WN 2654	1h 00m Denver	DEN 12:30 → SEA 14:25WN 4130	6h 30m	68%	24%
Southwest Details →	MDW 18:00 → DEN 19:45WN 1497	1h 25m Denver	DEN 21:10 → SEA 23:10WN 3856	7h 05m	72%	20%

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

DEN · 55m · leaves 05:15 2%

ATL · 57m · leaves 06:00 10%

DTW · 56m · leaves 09:17 16%

Afternoon and evening

DTW · 1h 02m · leaves 13:26 19%

ATL · 1h 13m · leaves 17:10 20%

MSP · 1h 17m · leaves 19:06 30%

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.

The table above includes two-ticket connections (marked “two tickets”), held to the 90-minute minimum. One ticket only →

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