Carrier route record
DLBOS→CHS
Delta Air Lines · Boston to Charleston
- Flights
- 390
- Period
- July 2025 to June 2026
- Share of route
- 35%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on BOS to CHS lands a B, level with the national rate of 77.6%. Roughly one flight in five arrives 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 390 flights, with a median arrival 5 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Delta on BOS to CHS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.0%
Arrivals under 15 minutes late, of 381 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
2.31%
National rate is 1.81%
Whole route
77.2%
Every carrier on BOS to CHS, 1,130 flights
These figures cover 390 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
Delta against every carrier on BOS to CHS
Delta flew 390 of the 1,130 flights on BOS to CHS, about 35% of it. Its 78.0% on time is about level with the route as a whole at 77.2%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Republic at 84.3% to JetBlue at 75.8%. 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 | 89 | 84.3% | 58 min | 0.00% | B+ |
| Delta Air Lines (this page) | 390 | 78.0% | 73 min | 2.31% | B |
| JetBlue Airways | 651 | 75.8% | 66 min | 1.69% | B |
Flight by flight
Delta flight numbers on BOS to CHS
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–8am6 flights—
- 8am–11am44 flights79.1%
- 11am–2pm329 flights78.5%
- 2pm–5pm11 flights—
- 5pm–8pm—
- 8pm–5am—
Scale runs 70% to 85%. Rows with fewer than 30 flights show a dash.
The 8am–11am window is the strongest at 79.1% on time. The full set of windows spans half a point.
Across the year
Delta on BOS to CHS through the year
April is the best month on the calendar at 91.2% 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, Wednesday is the strongest day at 83.7% on time and Sunday the weakest at 70.3%. 13 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Carrier accounts for 47% of the 6,135 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.
- 47%Carrier
- 33%Late-arriving aircraft
- 18%National Airspace System
- 2%Extreme weather
The largest share of delay minutes, 47%, 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 2,890 of the 6,135 delay minutes reported here. The split is drawn from 6,135 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 79.1% on time here.
Cancellations sit at 2.31% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
7.9% 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 a little over an hour, which a normal layover absorbs.
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 68.3% on time across 390 flights, 10 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 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 BOS to CHS
Put together: treat all of this as provisional. 390 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 78.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 381 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.