Route reliability record
SEA→CVG
Seattle to Cincinnati
- Flights
- 793
- Period
- July 2025 to June 2026
- Distance
- 1,965 mi
- Carriers
- 2
This route lands a B+, 4 points better than the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That is a workable record, not a spotless one. That rests on 793 SEA to CVG flights, with a median arrival 10 minutes early.
Best time to fly SEA to CVG: a 11am–2pm departure, ideally on a Wednesday. Flights in that window arrived on time 86.5% of the time and Wednesday flights 86.0%, against 81.7% for the route overall.
Set against the rest of the country, this route's record is 4 points better than the US average of 77.6%. That gap is worth roughly 41 fewer late arrivals for every thousand flights.
Key figures
On time
81.7%
Arrivals under 15 minutes late, of 781 completed flights
Avg delay
51 min
Across delayed arrivals only, not all flights
Cancelled
0.88%
National rate is 1.81%
Best carrier
Alaska
77.2% on time across 431 flights
These figures cover 793 flights between July 2025 and June 2026. The median arrival is 10 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
Which airline is most reliable on SEA to CVG
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Linesthin sample | 362 | 87.1% | 62 min | 0.83% | A+ |
| Alaska Airlines | 431 | 77.2% | 46 min | 0.93% | B+ |
Flight by flight
Flights on SEA to CVG
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 22 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–11am249 flights77.6%
- 11am–2pm474 flights86.5%
- 2pm–5pm—
- 5pm–8pm—
- 8pm–5am70 flights64.3%
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 64.3% on time, against 86.5% for the 11am–2pm slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 11am–2pm window is the busiest, with 474 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 28 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 63.3% on time, 28 points below September, the best at 91.7%. 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 92 flights.
Across the week, Wednesday is the strongest day at 86.0% on time and Sunday the weakest at 70.9%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Carrier accounts for 48% of the 7,312 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.
- 48%Carrier
- 32%Late-arriving aircraft
- 20%National Airspace System
The largest share of delay minutes, 48%, 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 3,515 of the 7,312 delay minutes reported here. The split is drawn from 7,312 reported delay minutes.
Cancellations are rare at 0.88%, 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 actually costs
Badly late arrivals are rare here: only 4.7% 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 is a different operation and performs like one: it runs 74.4% on time across 793 flights, 7 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 7 points of difference.
One caution: this is a thin sample. 793 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.
Work out the risk of missing a connection in CVG after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 793 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 81.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 781 completed flights over 12 months sit behind that.
Common questions
SEA to CVG questions
How often is SEA to CVG delayed?
Roughly one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 18.3% of the 793 flights in this analysis, against 22.4% nationally. Delayed flights are late by roughly 50 minutes on average.
How reliable is SEA to CVG compared with the rest of the country?
81.7% of flights arrive on time here against a national 77.6%, a difference of 4 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on SEA to CVG?
The 11am–2pm departure window is the strongest at 86.5% on time. The 8pm–5am window is the weakest at 64.3%, 22 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on SEA to CVG?
July is the weakest month at 63.3% on time, compared with 91.7% in September. Across the year that is 28 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- CVG to SEA — the return legseparate record
- Seattle-Tacoma International (SEA) delay statistics
- Cincinnati/Northern Kentucky International (CVG) delay statistics
- Delta Air Lines on SEA to CVG87.1%
- Alaska Airlines on SEA to CVG77.2%
- SEA to LAX, a related route83.4%
- ORD to CVG, a related route72.2%
- SEA to PHX, a related route79.2%
- Delta Air Lines on-time record87.1%
- Alaska Airlines on-time record77.2%
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. SEA to CVG and CVG to SEA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.