Carrier route record

DLCVG→SEA

Delta Air Lines · Cincinnati to Seattle

Flights: 362
Period: July 2025 to June 2026
Share of route: 46%
Carriers: 2

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

Delta on CVG to SEA earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 50 minutes. That rests on 362 flights, with a median arrival 8 minutes early.

Set against the rest of the country, Delta's CVG to SEA record is 7 points better than the US average of 77.6%. That gap is worth roughly 71 fewer late arrivals for every thousand flights.

On time

84.7%

Arrivals under 15 minutes late, of 360 completed flights

Avg delay

50 min

Across delayed arrivals only, not all flights

Cancelled

0.55%

National rate is 1.81%

Whole route

74.4%

Every carrier on CVG to SEA, 793 flights

These figures cover 362 flights between July 2025 and June 2026. The median arrival is 8 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

Delta against every carrier on CVG to SEA

Delta flew 362 of the 793 flights on CVG to SEA, about 46% of it. Its 84.7% on time is 10 points better than the route as a whole, which runs 74.4%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Delta at 84.7% to Alaska at 65.6%.

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 CVG to SEA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines (this page)thin sample	362	84.7%	50 min	0.55%	B+
Alaska Airlines	431	65.6%	54 min	1.62%	C

Flight by flight

Delta flight numbers on CVG to SEA

DL 96606:3085.5% · 346 flights

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 362 flights.

There are not enough flights in each departure window to split Delta's CVG to SEA record by time of day without the percentages moving on noise. The headline rate of 84.7% is the reliable figure here.

Across the year

Delta on CVG to SEA through the year

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

December is the weak month at 46.7% on time, against 100.0% in August. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. January was the busiest month here, with 31 flights.

Across the week, Tuesday is the strongest day at 88.7% on time and Friday the weakest at 80.4%. 8 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. National Airspace System accounts for 53% of the 2,725 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.

National Airspace System
53%
Carrier
45%
Extreme weather
1%

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 1,235 of the 2,725 delay minutes reported here. The split is drawn from 2,725 reported delay minutes.

53% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 1,450 minutes out of 2,725, against a national NAS share of 21%.

Cancellations are rare at 0.55%, 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 3.1% 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 1,965 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg runs 87.1% on time across 362 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 362 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 CVG to SEA

Put together: treat all of this as provisional. 362 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 84.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 360 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