Carrier route record

ASSEA→EUG

Alaska Airlines · Seattle to Eugene

Flights: 389
Period: July 2025 to June 2026
Share of route: 20%
Carriers: 2

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

Alaska on SEA to EUG sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land roughly 45 minutes behind schedule. That rests on 389 flights, with a median arrival 3 minutes early.

The national on-time rate over the same period is 77.6%, so Alaska on SEA to EUG runs 4 points behind the country as a whole. Across a thousand flights that is about 44 extra late arrivals.

On time

73.2%

Arrivals under 15 minutes late, of 385 completed flights

Avg delay

43 min

Across delayed arrivals only, not all flights

Cancelled

1.03%

National rate is 1.81%

Whole route

84.4%

Every carrier on SEA to EUG, 1,951 flights

These figures cover 389 flights between July 2025 and June 2026. The median arrival is 3 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 SEA to EUG

Alaska flew 389 of the 1,951 flights on SEA to EUG, about 20% of it. Its 73.2% on time is 11 points worse than the route as a whole, which runs 84.4%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 87.1% to Alaska at 73.2%.

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 SEA to EUG
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	1,562	87.1%	61 min	1.34%	A
Alaska Airlines (this page)	389	73.2%	43 min	1.03%	C

Flight by flight

Alaska flight numbers on SEA to EUG

AS 16123:1074.8% · 254 flights

Departure window

When Alaska runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 21 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am—
8am–11am—
11am–2pm95 flights65.3%
2pm–5pm—
5pm–8pm37 flights86.5%
8pm–5am257 flights74.3%

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

The weak window here is the middle of the day, not the evening: 11am–2pm runs 65.3% on time against 86.5% for 5pm–8pm. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8pm–5am window is the busiest, with 257 flights scheduled in it.

Across the year

Alaska on SEA to EUG through the year

Jul–Sep 2025184 flights65.6%
Oct–Dec 202594 flights71.7%
Jan–Mar 202690 flights87.6%
Apr–Jun 202621 flights—

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 73.2% on time across 389 flights.

Alaska on SEA to EUG did not run the same all year. Its best quarter was Jan–Mar 2026 at 87.6% on time and its weakest Jul–Sep 2025 at 65.6%, a swing of 22 points on roughly 130 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Across the week, Thursday is the strongest day at 79.6% on time and Monday the weakest at 60.0%. 20 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 57% of the 4,440 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
57%
Carrier
33%
National Airspace System
9%
Security
1%
Extreme weather
1%

57% 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 4,440 reported delay minutes here, that single category outweighs weather by 57 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 4,440 reported delay minutes.

Cancellations sit at 1.03% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

6.0% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 45 minutes, which a normal layover absorbs.

At 234 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 5pm–8pm window matters as much as it does.

The return leg is a different operation and performs like one: it runs 86.2% on time across 389 flights, 13 points above 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 13 points of difference.

One caution: this is a thin sample. 389 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 SEA to EUG

Put together: treat all of this as provisional. 389 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 73.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 385 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