Carrier route record

WNDEN→CVG

Southwest Airlines · Denver to Cincinnati

Flights: 364
Period: July 2025 to June 2026
Share of route: 24%
Carriers: 4

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

Southwest on DEN to CVG draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about 50 minutes behind schedule. Build slack into anything you connect to. That rests on 364 flights. The strongest carrier on the route with a full sample, United Airlines, flew 728 at 82.7% on time.

The national on-time rate over the same period is 77.6%, so Southwest on DEN to CVG runs 10 points behind the country as a whole. Across a thousand flights that is about 100 extra late arrivals.

On time

67.6%

Arrivals under 15 minutes late, of 358 completed flights

Avg delay

50 min

Across delayed arrivals only, not all flights

Cancelled

1.37%

National rate is 1.81%

Whole route

77.6%

Every carrier on DEN to CVG, 1,520 flights

These figures cover 364 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

Southwest against every carrier on DEN to CVG

Southwest flew 364 of the 1,520 flights on DEN to CVG, about 24% of it. Its 67.6% on time is 10 points worse than the route as a whole, which runs 77.6%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from United at 82.7% to Southwest at 67.6%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on DEN to CVG
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	728	82.7%	54 min	0.55%	B+
Frontier Airlines	402	77.4%	70 min	1.00%	B
Allegiant Airthin sample	26	73.1%	72 min	0.00%	C+
Southwest Airlines (this page)thin sample	364	67.6%	50 min	1.37%	C

No carrier stands out. United tops the table at 82.7%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.

Departure window

When Southwest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am—
8am–11am82 flights84.1%
11am–2pm98 flights77.1%
2pm–5pm179 flights56.6%
5pm–8pm5 flights—
8pm–5am—

Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 84.1% of the time, against 56.6% for the afternoon window. That is 27 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 179 flights scheduled in it.

Across the year

Southwest on DEN to CVG through the year

Darker means more delays. Figures are on-time percentages.May best, June worst

June is the worst month at 46.7% on time, 34 points below May, the best at 80.6%. 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. March was the busiest month here, with 31 flights.

Across the week, Wednesday is the strongest day at 78.8% on time and Thursday the weakest at 58.8%. 20 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 53% of the 5,799 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
53%
Carrier
34%
National Airspace System
12%
Extreme weather
1%

53% 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 5,799 reported delay minutes here, that single category outweighs weather by 40 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 5,799 reported delay minutes.

The largest share of delay minutes, 34%, 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 1,981 of the 5,799 delay minutes reported here.

Cancellations sit at 1.37% against a national 1.81%, which is ordinary. Diversions add another 0.27%.

Connections and stage length

What a delay here costs

7.3% 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 1,069 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 72.3% on time across 364 flights, 5 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 5 points of difference.

One caution: this is a thin sample. 364 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 Southwest on DEN to CVG

Put together: treat all of this as provisional. 364 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 67.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 358 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