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 85% on time.

Nonstops


Delta	SEA	BOI	1h 34m	89%	0.2%	2,362	Flying now
Alaska	SEA	BOI	1h 28m	83%	0.4%	2,941	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Boise on time. Total trip = scheduled departure to arrival, layover included (Boise is 1 h ahead of Seattle). Layovers up to 4 hours. Pick a connection for the details.


Alaska Details →	SEA 06:42 → PDX 07:37AS 2432 · flown by Horizon	2h 53m Portland	PDX 10:30 → BOI 12:49AS 2089 · flown by Horizon	5h 07m	100%	94%
Alaska Details →	SEA 07:28 → SMF 09:26AS 682	3h 44m Sacramento	SMF 13:10 → BOI 15:35AS 2157 · flown by Horizon	7h 07m	100%	91%
Delta Details →	SEA 05:30 → SLC 08:30DL 1128	2h 30m Salt Lake City	SLC 11:00 → BOI 12:15DL 1442	5h 47m	98%	91%
Alaska Details →	SEA 06:40 → BUR 09:12AS 488	1h 48m Burbank	BUR 11:00 → BOI 14:09AS 3209 · flown by SkyWest	6h 29m	98%	87%
Delta Details →	SEA 07:15 → LAX 10:05DL 1628	1h 39m Los Angeles	LAX 11:44 → BOI 14:46DL 3773 · flown by SkyWest	6h 36m	97%	87%
Alaska Details →	SEA 14:18 → SJC 16:32AS 1366	3h 16m San Jose	SJC 19:48 → BOI 22:33AS 3413 · flown by SkyWest	7h 15m	100%	86%
Alaska Details →	SEA 10:14 → PDX 11:21AS 3090 · flown by SkyWest	3h 37m Portland	PDX 14:58 → BOI 17:16AS 342	6h 02m	100%	86%
Alaska Details →	SEA 14:22 → GEG 15:25AS 2180 · flown by Horizon	3h 59m Spokane	GEG 19:24 → BOI 21:38AS 3215 · flown by SkyWest	6h 16m	100%	85%
Tight connection: often missed
United Details →	SEA 15:33 → SFO 17:47UA 2866	58m San Francisco	SFO 18:45 → BOI 21:40UA 5644 · flown by SkyWest	5h 07m	55%	43%
Southwest Details →	SEA 10:25 → OAK 12:35WN 1713	55m Oakland	OAK 13:30 → BOI 16:00WN 803	4h 35m	44%	36%
United Details →	SEA 07:00 → SFO 09:18UA 1578	57m San Francisco	SFO 10:15 → BOI 13:08UA 6035 · flown by SkyWest	5h 08m	11%	6%

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

SNA · 1h 18m · leaves 08:18 6%

SAN · 1h 20m · leaves 06:21 7%

PHX · 55m · leaves 06:16 8%

Afternoon and evening

PDX · 1h 13m · leaves 19:22 15%

LAX · 1h 01m · leaves 15:59 22%

SFO · 58m · leaves 15:33 45%

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.


Southwest WN 3630 SEA 07:35 → SMF Alaska AS 2157 SMF 13:10 → BOI Connection details →	3h 35m	7h 00m	100%	91%
Delta DL 3953 SEA 07:30 → PDX Alaska AS 2089 PDX 10:30 → BOI Connection details →	1h 51m	4h 19m	95%	91%
Delta DL 3802 SEA 10:35 → PDX Alaska AS 342 PDX 14:58 → BOI Connection details →	3h 16m	5h 41m	97%	84%

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