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

No clear winner: Alaska’s SEA → BIL flights land within a few points of 85% on time whatever the hour.

Nonstops (seasonal or thin)


Alaska	SEA	BIL	1h 54m	85%	0.8%	918	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

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


Alaska Details →	SEA 08:45 → PDX 09:49AS 3132 · flown by SkyWest	2h 24m Portland	PDX 12:13 → BIL 15:03AS 2368 · flown by Horizon	5h 18m	100%	94%
Delta Details →	SEA 05:30 → SLC 08:30DL 1128	1h 10m Salt Lake City	SLC 09:40 → BIL 11:09DL 4038 · flown by SkyWest	4h 39m	96%	91%
Delta Details →	SEA 09:30 → SLC 12:38DL 1016	3h 55m Salt Lake City	SLC 16:33 → BIL 18:00DL 3828 · flown by SkyWest	7h 30m	99%	87%
United Details →	SEA 12:50 → DEN 16:42UA 1351	2h 58m Denver	DEN 19:40 → BIL 21:17UA 1417	7h 27m	99%	80%
United Details →	SEA 05:00 → DEN 08:43UA 2601	3h 02m Denver	DEN 11:45 → BIL 13:22UA 703	7h 22m	99%	79%
United Details →	SEA 15:40 → DEN 19:29UA 325	1h 41m Denver	DEN 21:10 → BIL 22:54UA 5257 · flown by SkyWest	6h 14m	97%	78%
United Details →	SEA 08:56 → DEN 12:45UA 1505	1h 00m Denver	DEN 13:45 → BIL 15:29UA 5845 · flown by SkyWest	5h 33m	92%	75%

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

SLC · 1h 10m · leaves 05:30 4%

PDX · 52m · leaves 10:14 7%

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 3953 SEA 07:30 → PDX Alaska AS 2368 PDX 12:13 → BIL Connection details →	3h 34m	6h 33m	100%	94%
Southwest WN 3397 SEA 07:50 → DEN United UA 5845 DEN 13:45 → BIL Connection details →	2h 20m	6h 39m	98%	81%
Southwest WN 3615 SEA 05:15 → DEN United UA 703 DEN 11:45 → BIL Connection details →	2h 55m	7h 07m	96%	77%

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