Route reliability record
CHS→MIA
Charleston to Miami
- Flights
- 953
- Period
- September 2025 to August 2026
- Distance
- 489 mi
- Carriers
- 3
This route lands a B, 3 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by close to two hours on average. That rests on 953 CHS to MIA flights, with a median arrival 8 minutes early.
Best time to fly CHS to MIA: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 89.4% of the time and Wednesday flights 86.5%, against 80.1% for the route overall.
The US average over the same twelve months is 77.3%, 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 937 completed flights
Avg delay
102 min
Across delayed arrivals only, not all flights
Cancelled
1.26%
National rate is 1.89%
Best carrier
American
79.6% on time across 885 flights
These figures cover 953 flights between September 2025 and August 2026. Beyond the headline rate, 8.8% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on CHS 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Airthin sample | 53 | 90.6% | 68 min | 0.00% | A+ |
| American Airlines | 885 | 79.6% | 104 min | 1.13% | B |
| Republic Airwaysthin sample | 15 | 76.9% | 32 min | 13.33% | B− |
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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 26 points, against half a point between the best and worst carrier.
- 5am–8am365 flights89.4%
- 8am–11am157 flights88.5%
- 11am–2pm132 flights78.5%
- 2pm–5pm—
- 5pm–8pm86 flights68.3%
- 8pm–5am213 flights63.8%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 63.8% on time, against 89.4% for the 5am–8am 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 5am–8am window is the busiest, with 365 flights scheduled in it.
Explore
Filter CHS to MIA by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On CHS to MIA, the best departure window is 5am–8am at 89.4% on time and the worst is 8pm–5am at 63.8%, a wide gap of 25.6 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am89.4%
- 8–11am88.5%
- 11am–2pm78.5%
- 2–5pm—
- 5–8pm68.3%
- 8pm–5am63.8%
best all US flightsScale 55% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 13 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.
Delays peak in May, when the on-time rate falls to 72.6%. February is the strongest month at 85.4%. Moving a flexible trip across that boundary buys 13 points. March was the busiest month here, with 93 flights.
Across the week, Wednesday is the strongest day at 86.5% on time and Sunday the weakest at 68.1%, a spread of 18 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 60% of the 19,000 delay minutes carriers reported here, and the remaining four split what is left.
- 60%Late-arriving aircraft
- 28%Carrier
- 11%National Airspace System
- 1%Extreme weather
60% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 19,000 reported delay minutes here, that single category outweighs weather by 44 to one. The split is drawn from 19,001 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 89.4% on time here.
Cancellations sit at 1.26% against a national 1.89%, which is ordinary. Diversions add another 0.42%.
Connections and stage length
What a delay here actually costs
8.8% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last close to two hours, which a normal layover absorbs.
At 489 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 68.2% on time across 952 flights, 12 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 12 points of difference.
One caution: this is a thin sample. 953 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. 953 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. 937 completed flights over 12 months sit behind that.
Common questions
CHS to MIA questions
How often is CHS 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 953 flights in this analysis, against 22.7% nationally. Delayed flights are late by close to two hours on average.
How reliable is CHS to MIA compared with the rest of the country?
80.1% of flights arrive on time here against a national 77.3%, 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 CHS to MIA?
The 5am–8am departure window is the strongest at 89.4% on time. The 8pm–5am window is the weakest at 63.8%, 26 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 May delays on CHS to MIA?
May is the weakest month at 72.6% on time, compared with 85.4% in February. Across the year that is 13 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
- MIA to CHS — the return legseparate record
- Charleston International (CHS) delay statistics
- Miami International (MIA) delay statistics
- CHS to ATL, a related route88.9%
- ATL to MIA, a related route71.2%
- CHS to CLT, a related route82.7%
- Envoy Air on-time record90.6%
- American Airlines on-time record79.6%
- Republic Airways on-time record76.9%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. CHS to MIA and MIA to CHS 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.