Carrier route record
DLCHS→BOS
Delta Air Lines · Charleston to Boston
- Flights
- 390
- Period
- July 2025 to June 2026
- Share of route
- 34%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on CHS to BOS sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 390 flights, with a median arrival 6 minutes early.
The national on-time rate over the same period is 77.6%, so Delta on CHS to BOS runs 9 points behind the country as a whole. Across a thousand flights that is about 93 extra late arrivals.
Key figures
On time
68.3%
Arrivals under 15 minutes late, of 379 completed flights
Avg delay
90 min
Across delayed arrivals only, not all flights
Cancelled
2.82%
National rate is 1.81%
Whole route
71.3%
Every carrier on CHS to BOS, 1,131 flights
These figures cover 390 flights between July 2025 and June 2026. Beyond the headline rate, 14.2% 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
Delta against every carrier on CHS to BOS
Delta flew 390 of the 1,131 flights on CHS to BOS, about 34% of it. Its 68.3% on time is 3 points worse than the route as a whole, which runs 71.3%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Republic at 84.3% to Delta at 68.3%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 90 | 84.3% | 90 min | 1.11% | B |
| JetBlue Airways | 651 | 71.2% | 77 min | 1.84% | C |
| Delta Air Lines (this page) | 390 | 68.3% | 90 min | 2.82% | C |
Flight by flight
Delta flight numbers on CHS to BOS
Departure window
When Delta runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 390 flights.
- 5am–8am—
- 8am–11am—
- 11am–2pm48 flights74.5%
- 2pm–5pm327 flights67.5%
- 5pm–8pm15 flights—
- 8pm–5am—
Scale runs 60% to 80%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 74.5% on time, ahead of 2pm–5pm at 67.5%. 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 2pm–5pm window is the busiest, with 327 flights scheduled in it.
Across the year
Delta on CHS to BOS through the year
April is the best month on the calendar at 79.4% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. July was the busiest month here, with 42 flights.
Across the week, Saturday is the strongest day at 78.6% on time and Thursday the weakest at 62.0%. 17 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
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 11,000 reported delay minutes.
- 38%National Airspace System
- 32%Carrier
- 29%Late-arriving aircraft
- 1%Extreme weather
38% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 4,125 minutes out of 11,000, against a national NAS share of 21%. The split is drawn from 10,749 reported delay minutes.
Cancellations run at 2.82%, against 1.81% nationally. That is roughly 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 costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 14.2% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 818 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 78.0% on time across 390 flights, 10 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 10 points of difference.
One caution: this is a thin sample. 390 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 Delta on CHS to BOS
Put together: the delay figures matter less here than the 2.82% cancellation rate. A late arrival costs you an hour and a half; a cancelled flight costs you the day. Book the 11am–2pm departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 379 completed flights over 12 months sit behind that.
Related
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.