Carrier route record

DLSEA→JNU

Delta Air Lines · Seattle to Juneau

Flights: 141
Period: July 2025 to June 2026
Share of route: 9%
Carriers: 2

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

Delta on SEA to JNU lands a B+, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 45 minutes on average. That is a workable record, not a spotless one. That rests on 141 flights, with a median arrival right on schedule.

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

On time

80.0%

Arrivals under 15 minutes late, of 140 completed flights

Avg delay

43 min

Across delayed arrivals only, not all flights

Cancelled

0.71%

National rate is 1.81%

Whole route

76.6%

Every carrier on SEA to JNU, 1,589 flights

These figures cover 141 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Carrier by carrier

Delta against every carrier on SEA to JNU

Delta flew 141 of the 1,589 flights on SEA to JNU, about 9% of it. Its 80.0% on time is 3 points better than the route as a whole, which runs 76.6%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Delta at 80.0% to Alaska at 76.3%.

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 JNU
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines (this page)thin sample	141	80.0%	43 min	0.71%	B+
Alaska Airlines	1,448	76.3%	48 min	1.45%	B

Departure window

When Delta 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 141 flights.

There are not enough flights in each departure window to split Delta's SEA to JNU record by time of day without the percentages moving on noise. The headline rate of 80.0% is the reliable figure here.

Across the year

Delta on SEA to JNU through the year

Jul–Sep 202592 flights79.3%
Oct–Dec 202525 flights—
Apr–Jun 202624 flights—

Scale runs 70% to 85%. 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 80.0% on time across 141 flights.

Split by quarter, Delta on SEA to JNU logged 92 flights in Jul–Sep 2025, 25 flights in Oct–Dec 2025 and 24 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 80.0% annual figure is the one to use.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 66% of the 1,216 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
66%
Late-arriving aircraft
22%
National Airspace System
11%

The largest share of delay minutes, 66%, 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 807 of the 1,216 delay minutes reported here. The split is drawn from 1,216 reported delay minutes.

Cancellations are rare at 0.71%, 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

5.7% 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.

The 909 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 92.1% on time across 141 flights, 12 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 12 points of difference.

One caution: this is a thin sample. 141 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 Delta on SEA to JNU

Put together: treat all of this as provisional. 141 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 80.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 140 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