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DelayAtlas

Route reliability record

CHSPHL

Charleston to Philadelphia

Flights
1,109
Period
July 2025 to June 2026
Distance
550 mi
Carriers
4
BGRADE

This route lands a B, about a point 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 an hour and a half on average. That is a workable record, not a spotless one. That rests on 1,109 CHS to PHL flights, with a median arrival 9 minutes early.

Best time to fly CHS to PHL: a 11am–2pm departure, ideally on a Monday. Flights in that window arrived on time 86.5% of the time and Monday flights 83.5%, against 78.8% 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

78.8%

Arrivals under 15 minutes late, of 1,086 completed flights

Avg delay

94 min

Across delayed arrivals only, not all flights

Cancelled

1.98%

National rate is 1.81%

Best carrier

American

79.4% on time across 736 flights

These figures cover 1,109 flights between July 2025 and June 2026. Beyond the headline rate, 8.0% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Which airline is most reliable on CHS to PHL

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 CHS to PHL
AirlineFlightsOn timeAvg delayCancelledGrade
Republic Airwaysthin sample3491.2%38 min0.00%A+
American Airlines73679.4%92 min1.63%B
PSA Airlinesthin sample26578.5%114 min3.40%B−
Frontier Airlinesthin sample7468.5%65 min1.35%C

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 18 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–8am207 flights85.8%
  • 8am–11am34 flights78.8%
  • 11am–2pm337 flights86.5%
  • 2pm–5pm289 flights69.0%
  • 5pm–8pm242 flights73.7%
  • 8pm–5am

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 11am–2pm slot at 86.5% on time, ahead of 2pm–5pm at 69.0%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 11am–2pm window is the busiest, with 337 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 18 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 month78J88F81M81A81M80J70J83A81S77O78N74D
Darker means more delays. Figures are on-time percentages.February best, July worst

July is the worst month at 69.7% on time, 18 points below February, the best at 88.1%. 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. August was the busiest month here, with 126 flights.

Across the week, Monday is the strongest day at 83.5% on time and Thursday the weakest at 73.8%. 10 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week83.5Mon82.3Tue77.5Wed73.8Thu79.2Fri78.8Sat76.9Sun
Monday: 83.5 percent on time. Tuesday: 82.3 percent on time. Wednesday: 77.5 percent on time. Thursday: 73.8 percent on time. Friday: 79.2 percent on time. Saturday: 78.8 percent on time. Sunday: 76.9 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 52% of the 22,000 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
    52%
  • Carrier
    35%
  • National Airspace System
    12%
  • Extreme weather
    1%

52% 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 22,000 reported delay minutes here, that single category outweighs weather by 52 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 21,603 reported delay minutes.

The largest share of delay minutes, 35%, 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 7,598 of the 22,000 delay minutes reported here.

Cancellations sit at 1.98% against a national 1.81%, which is ordinary. Diversions add another 0.09%.

Connections and stage length

What a delay here actually costs

8.0% 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 an hour and a half, which a normal layover absorbs.

The 550 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 77.5% on time across 1,109 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,109 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

Work out the risk of missing a connection in PHL after this flight

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 88.1% on time and July 69.7%, a swing of 18 points. If the dates move at all, move them out of July before you think about anything else. 1,086 completed flights over 12 months sit behind that.

Common questions

CHS to PHL questions

How often is CHS to PHL 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 21.2% of the 1,109 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.

How reliable is CHS to PHL compared with the rest of the country?

78.8% of flights arrive on time here against a national 77.6%, a difference of about a point 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 PHL?

The 11am–2pm departure window is the strongest at 86.5% on time. The 2pm–5pm window is the weakest at 69.0%, 18 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 CHS to PHL?

July is the weakest month at 69.7% on time, compared with 88.1% in February. Across the year that is 18 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. CHS to PHL and PHL to CHS are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Embed CHS to PHL’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

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.