Carrier route record

ASBOI→PDX

Alaska Airlines · Boise to Portland

Flights: 658
Period: July 2025 to June 2026
Share of route: 59%
Carriers: 2

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.

Alaska on BOI to PDX earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 14 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 658 flights, with a median arrival 11 minutes early.

Set against the rest of the country, Alaska's BOI to PDX record is 14 points better than the US average of 77.6%. That gap is worth roughly 140 fewer late arrivals for every thousand flights.

On time

91.6%

Arrivals under 15 minutes late, of 657 completed flights

Avg delay

56 min

Across delayed arrivals only, not all flights

Cancelled

0.15%

National rate is 1.81%

Whole route

91.9%

Every carrier on BOI to PDX, 1,115 flights

These figures cover 658 flights between July 2025 and June 2026. The median arrival is 11 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Carrier by carrier

Alaska against every carrier on BOI to PDX

Alaska flew 658 of the 1,115 flights on BOI to PDX, most of the route. Its 91.6% on time is about level with the route as a whole at 91.9%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 92.3% to Alaska at 91.6%.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on BOI to PDX
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	457	92.3%	63 min	1.09%	A
Alaska Airlines (this page)	658	91.6%	56 min	0.15%	A+

Departure window

When Alaska runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 658 flights.

5am–8am219 flights97.2%
8am–11am58 flights93.1%
11am–2pm31 flights90.3%
2pm–5pm330 flights87.3%
5pm–8pm—
8pm–5am20 flights—

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 97.2% of the time, against 87.3% for the afternoon window. That is 10 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 330 flights scheduled in it.

Across the year

Alaska on BOI to PDX through the year

Darker means more delays. Figures are on-time percentages.October best, August worst

August is the worst month at 80.0% on time, 20 points below October, the best at 100.0%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. January was the busiest month here, with 97 flights.

Across the week, Tuesday is the strongest day at 96.7% on time and Friday the weakest at 85.0%. 12 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Alaska runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 65% of the 3,090 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Late-arriving aircraft
65%
Carrier
25%
National Airspace System
9%
Extreme weather
1%

65% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 3,090 reported delay minutes here, that single category outweighs weather by 45 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 3,090 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 97.2% on time here.

Cancellations are rare at 0.15%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 2.3% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

At 344 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 85.7% on time across 659 flights, 6 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 6 points of difference.

One caution: this is a thin sample. 658 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Alaska on BOI to PDX

Put together: treat all of this as provisional. 658 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 91.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 657 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures