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

No clear winner: airlines and hours on this route all land within a few points of 82% on time.

Nonstops (seasonal or thin)


Alaska	SEA	BWI	5h 08m	85%	0.5%	599	Flying now
Southwest	SEA	BWI	4h 55m	64%	0.0%	120	Flying now

Best connections, any airlines

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Baltimore on time. Total trip = scheduled departure to arrival, layover included (Baltimore is 3 h ahead of Seattle). Layovers up to 4 hours. Pick a connection for the details.


Delta + Southwesttwo ticketsDetails →	SEA 16:20 → LAS 18:57DL 2955	3h 13m Las Vegas	LAS 22:10 → BWI 05:45 +1WN 2208	10h 25m	99%	92%
Southwest Details →	SEA 23:05 → MDW 05:00WN 2304	3h 55m Chicago	MDW 08:55 → BWI 11:45 +1WN 1355	9h 40m	100%	90%
Alaska + Southwesttwo ticketsDetails →	SEA 21:33 → RDU 05:40AS 677	3h 00m Raleigh/Durham	RDU 08:40 → BWI 09:50 +1WN 4550	9h 17m	99%	90%
Alaska + Southwesttwo ticketsDetails →	SEA 21:33 → MCO 06:16AS 394	2h 24m Orlando	MCO 08:40 → BWI 10:55 +1WN 2611	10h 22m	97%	89%
Alaska + Unitedtwo ticketsDetails →	SEA 17:10 → LAX 19:55AS 492	3h 10m Los Angeles	LAX 23:05 → BWI 07:14 +1UA 1605	11h 04m	98%	89%
Delta Details →	SEA 22:58 → ATL 06:45DL 409	2h 10m Atlanta	ATL 08:55 → BWI 10:47 +1DL 801	8h 49m	100%	89%
United Details →	SEA 05:15 → SFO 07:35UA 5676 · flown by SkyWest	1h 58m San Francisco	SFO 09:33 → BWI 17:57UA 2664	9h 42m	99%	88%
American + Southwesttwo ticketsDetails →	SEA 15:20 → PHX 18:25AA 3440 · flown by Envoy	4h 00m Phoenix	PHX 22:25 → BWI 05:40 +1WN 1170	11h 20m	96%	88%
Tight connection: often missed
United Details →	SEA 13:55 → ORD 20:21UA 2101	59m Chicago	ORD 21:20 → BWI 00:28 +1UA 675	7h 33m	64%	37%
Southwest Details →	SEA 11:45 → MDW 18:00WN 3081	1h 00m Chicago	MDW 19:00 → BWI 21:55WN 2745	7h 10m	57%	35%
Delta Details →	SEA 11:15 → BOS 19:43DL 438	52m Boston	BOS 20:35 → BWI 22:29DL 5851 · flown by Republic	8h 09m	54%	31%

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 · 1h 03m · leaves 05:00 3%

ATL · 1h 09m · leaves 23:59 8%

IAH · 55m · leaves 05:00 11%

Afternoon and evening

MDW · 1h 00m · leaves 11:45 43%

BOS · 52m · leaves 11:15 46%

ORD · 59m · leaves 13:58 56%

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