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, one ticket

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.


Southwest Details →	SEA 23:05 → MDW 05:00WN 2304	3h 55m Chicago	MDW 08:55 → BWI 11:45 +1WN 1355	9h 40m	100%	90%
United Details →	SEA 17:04 → LAX 19:53UA 1730	3h 12m Los Angeles	LAX 23:05 → BWI 07:14 +1UA 1605	11h 10m	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%
Delta Details →	SEA 23:59 → MSP 05:17DL 953	1h 53m Minneapolis	MSP 07:10 → BWI 10:42 +1DL 2357	7h 43m	98%	88%
Delta Details →	SEA 23:59 → ATL 07:46DL 652	3h 24m Atlanta	ATL 11:10 → BWI 13:03 +1DL 2711	10h 04m	99%	87%
United Details →	SEA 05:00 → DEN 08:43UA 2601	1h 03m Denver	DEN 09:46 → BWI 15:17UA 1362	7h 17m	97%	85%
Delta Details →	SEA 21:45 → ATL 05:36DL 567	1h 59m Atlanta	ATL 07:35 → BWI 09:24 +1DL 1592	8h 39m	98%	85%
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.


Delta DL 2955 SEA 16:20 → LAS Southwest WN 2208 LAS 22:10 → BWI Connection details →	3h 13m	10h 25m	99%	92%
Alaska AS 677 SEA 21:33 → RDU Southwest WN 4550 RDU 08:40 → BWI Connection details →	3h 00m	9h 17m	99%	90%
Alaska AS 394 SEA 21:33 → MCO Southwest WN 2611 MCO 08:40 → BWI Connection details →	2h 24m	10h 22m	97%	89%

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