Route reliability record

BOS→CLT

Boston to Charlotte

Flights: 4,017
Period: July 2025 to June 2026
Distance: 728 mi
Carriers: 4

This route lands a B, 5 points better than the national rate of 77.6%. About one flight in six arrive 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 4,017 flights, of which American Airlines flew 2,735 at 83.8% on time.

Set against the rest of the country, this route's record is 5 points better than the US average of 77.6%. That gap is worth roughly 50 fewer late arrivals for every thousand flights.

On time

82.6%

Arrivals under 15 minutes late, of 3,904 completed flights

Avg delay

82 min

Across delayed arrivals only, not all flights

Cancelled

2.69%

National rate is 1.81%

Best carrier

American

83.8% on time across 2,735 flights

These figures cover 4,017 flights between July 2025 and June 2026. The median arrival is 14 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 BOS to CLT

The two carriers here are closely matched: 3 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 BOS to CLT
Airline	Flights	On time	Avg delay	Cancelled	Grade
Envoy Airthin sample	5	100.0%	—	20.00%	A−
American Airlines	2,735	83.8%	90 min	2.34%	B
Republic Airways	1,199	80.5%	67 min	3.42%	B−
Spirit Airlinesthin sample	78	71.1%	85 min	2.56%	C

Republic Airways cancels 3.4% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

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 35 points, against 3 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am784 flights94.0%
8am–11am815 flights87.3%
11am–2pm772 flights85.4%
2pm–5pm762 flights75.7%
5pm–8pm837 flights72.0%
8pm–5am47 flights58.7%

Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 58.7% on time, against 94.0% 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 5pm–8pm window is the busiest, with 837 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 19 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.

Darker means more delays. Figures are on-time percentages.April best, September worst

April is the best month on the calendar at 90.6% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. October was the busiest month here, with 370 flights.

Across the week, Wednesday is the strongest day at 86.3% on time and Sunday the weakest at 78.0%. 8 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. Late-arriving aircraft accounts for 45% of the 56,000 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
45%
Carrier
33%
National Airspace System
16%
Extreme weather
6%
Security
0%

45% 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 56,000 reported delay minutes here, that single category outweighs weather by 8 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 55,624 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 94.0% on time here.

Cancellations run at 2.69%, against 1.81% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here actually costs

7.1% 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 are the a little over an hour kind, which a normal layover absorbs.

The 728 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 76.2% on time across 4,016 flights, 6 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 6 points of difference.

The sample behind these figures is 4,017 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.

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 90.6% on time and September 71.8%, a swing of 19 points. If the dates move at all, move them out of September before you think about anything else. 3,904 completed flights over 12 months sit behind that.

Common questions

BOS to CLT questions

How often is BOS to CLT delayed?

About one flight in six arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 17.4% of the 4,017 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on BOS to CLT?

American Airlines leads at 83.8% on time across 2,735 flights. Republic Airways is at the other end on 80.5%, a gap of 3 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on BOS to CLT?

The 5am–8am departure window is the strongest at 94.0% on time. The 8pm–5am window is the weakest at 58.7%, 35 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 September delays on BOS to CLT?

September is the weakest month at 71.8% on time, compared with 90.6% in April. Across the year that is 19 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. BOS to CLT and CLT to BOS are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures