Skip to content
DelayAtlas

Carrier route record

ASSEABZN

Alaska Airlines · Seattle to Bozeman

Flights
623
Period
July 2025 to June 2026
Share of route
40%
Carriers
3
B+GRADE

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

Alaska on SEA to BZN sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about 50 minutes behind schedule. That rests on 623 flights, with a median arrival 3 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Alaska on SEA to BZN from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

75.9%

Arrivals under 15 minutes late, of 617 completed flights

Avg delay

51 min

Across delayed arrivals only, not all flights

Cancelled

0.96%

National rate is 1.81%

Whole route

82.8%

Every carrier on SEA to BZN, 1,572 flights

These figures cover 623 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 BZN

Alaska flew 623 of the 1,572 flights on SEA to BZN, about 40% of it. Its 75.9% on time is 7 points worse than the route as a whole, which runs 82.8%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Delta at 100.0% to Alaska at 75.9%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

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 BZN
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Linesthin sample1100.0%0.00%A+
SkyWest Airlines94887.4%51 min0.21%A+
Alaska Airlines (this page)62375.9%51 min0.96%B+

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 12 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–2pm299 flights76.9%
  • 2pm–5pm135 flights67.9%
  • 5pm–8pm
  • 8pm–5am189 flights79.8%

Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is the strongest at 79.8% on time. The full set of windows spans 12 points.

Across the year

Alaska on SEA to BZN through the year

On-time rate by calendar month85J89F83M85A80M80J53J67A72S76O78N70D
Darker means more delays. Figures are on-time percentages.February best, July worst

July is the worst month at 53.3% on time, 36 points below February, the best at 88.9%. 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. July was the busiest month here, with 61 flights.

Across the week, Sunday is the strongest day at 79.8% on time and Thursday the weakest at 71.3%. 9 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week78.4Mon78.8Tue73.2Wed71.3Thu77.4Fri72.0Sat79.8Sun
Monday: 78.4 percent on time. Tuesday: 78.8 percent on time. Wednesday: 73.2 percent on time. Thursday: 71.3 percent on time. Friday: 77.4 percent on time. Saturday: 72.0 percent on time. Sunday: 79.8 percent on time

Delay causes

Why Alaska runs late on this route

One category carries most of the weight here. Carrier accounts for 45% of the 7,534 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.

  • Carrier
    45%
  • Late-arriving aircraft
    39%
  • National Airspace System
    14%
  • Extreme weather
    1%
  • Security
    0%

39% 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 7,534 reported delay minutes here, that single category outweighs weather by 39 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 7,534 reported delay minutes.

The largest share of delay minutes, 45%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 3,396 of the 7,534 delay minutes reported here.

Cancellations sit at 0.96% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

6.5% 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 about 50 minutes, which a normal layover absorbs.

The 543 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg is a different operation and performs like one: it runs 81.5% on time across 622 flights, 6 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 6 points of difference.

One caution: this is a thin sample. 623 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 BZN

Put together: treat all of this as provisional. 623 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 75.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 617 completed flights over 12 months sit behind that.

Related

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.