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DelayAtlas

Route reliability record

CVGMIA

Cincinnati to Miami

Flights
998
Period
July 2025 to June 2026
Distance
948 mi
Carriers
5
B+GRADE

This route lands a B+, 3 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 about an hour on average. That is a workable record, not a spotless one. That rests on 998 CVG to MIA flights, with a median arrival 5 minutes early.

Best time to fly CVG to MIA: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 90.0% of the time and Tuesday flights 84.7%, against 80.1% for the route overall.

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

Key figures

On time

80.1%

Arrivals under 15 minutes late, of 986 completed flights

Avg delay

67 min

Across delayed arrivals only, not all flights

Cancelled

0.80%

National rate is 1.81%

Best carrier

Envoy

82.2% on time across 782 flights

These figures cover 998 flights between July 2025 and June 2026. The median arrival is 5 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 CVG to MIA

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 MIA
AirlineFlightsOn timeAvg delayCancelledGrade
Envoy Air78282.2%56 min0.64%B+
American Airlinesthin sample7675.3%139 min1.32%B
Frontier Airlinesthin sample12872.8%77 min1.56%C
Republic Airwaysthin sample1154.5%43 min0.00%F+
Delta Air Linesthin sample10.0%37 min0.00%F+

Flight by flight

Flights on CVG to MIA

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.

Best ways to make this trip

The most reliable ways to fly Cincinnati to Miami

Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 1 of the top 2 use a different airport at one end.

Most reliable ways to fly from CVG to MIA
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. CVGMIACincinnati to MiamiEnvoy Air81.7%82.2%0.64%5am–8am, SatMQ 3638 08:41
2. CVGFLLCincinnati to Fort LauderdaleDelta Air Lines77.3%78.3%1.31%5am–8am, WedDL 661 16:32

Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.

Plan this trip by month, day and time

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 20 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–8am442 flights90.0%
  • 8am–11am144 flights78.0%
  • 11am–2pm36 flights79.4%
  • 2pm–5pm8 flights
  • 5pm–8pm357 flights69.6%
  • 8pm–5am11 flights

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 90.0% of the time, against 69.6% for the evening window. That is 20 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 442 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 24 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.

On-time rate by calendar month83J74F80M89A90M82J70J80A73S82O92N68D
Darker means more delays. Figures are on-time percentages.November best, December worst

December is the weak month at 68.2% on time, against 91.8% in November. 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. March was the busiest month here, with 122 flights.

Across the week, Tuesday is the strongest day at 84.7% on time and Sunday the weakest at 73.8%. 11 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week81.8Mon84.7Tue83.1Wed79.7Thu80.4Fri78.3Sat73.8Sun
Monday: 81.8 percent on time. Tuesday: 84.7 percent on time. Wednesday: 83.1 percent on time. Thursday: 79.7 percent on time. Friday: 80.4 percent on time. Saturday: 78.3 percent on time. Sunday: 73.8 percent on time

Delay causes

Why this route gets delayed

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 13,000 reported delay minutes.

  • Late-arriving aircraft
    40%
  • Carrier
    33%
  • National Airspace System
    18%
  • Extreme weather
    9%
  • Security
    0%

40% 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 13,000 reported delay minutes here, that single category outweighs weather by 5 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 13,046 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 90.0% on time here.

Cancellations are rare at 0.80%, 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

6.7% 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 about an hour, which a normal layover absorbs.

The 948 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 runs 77.4% on time across 998 flights, within 3 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. 998 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 MIA after this flight

What to do with this

Booking this route

Put together: treat all of this as provisional. 998 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 80.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 986 completed flights over 12 months sit behind that.

Common questions

CVG to MIA questions

How often is CVG to MIA delayed?

About 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 19.9% of the 998 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

How reliable is CVG to MIA compared with the rest of the country?

80.1% of flights arrive on time here against a national 77.6%, a difference of 3 points in its favour. That is worth a B+ on this site's grading scale.

What time of day has the fewest delays on CVG to MIA?

The 5am–8am departure window is the strongest at 90.0% on time. The 5pm–8pm window is the weakest at 69.6%, 20 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 December delays on CVG to MIA?

December is the weakest month at 68.2% on time, compared with 91.8% in November. Across the year that is 24 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

Direction matters. CVG to MIA and MIA to CVG 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.