Route reliability record
BWI→CHS
Baltimore to Charleston
- Flights
- 1,241
- Period
- July 2025 to June 2026
- Distance
- 472 mi
- Carriers
- 2
This route lands a B, 3 points 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 about an hour on average. That is a workable record, not a spotless one. That rests on 1,241 BWI to CHS flights, with a median arrival 5 minutes early.
Best time to fly BWI to CHS: a 8am–11am departure, ideally on a Wednesday. Flights in that window arrived on time 90.0% of the time and Wednesday flights 85.7%, against 80.6% 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
80.6%
Arrivals under 15 minutes late, of 1,221 completed flights
Avg delay
60 min
Across delayed arrivals only, not all flights
Cancelled
1.37%
National rate is 1.81%
Best carrier
Southwest
80.6% on time across 1,229 flights
These figures cover 1,241 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
Which airline is most reliable on BWI to CHS
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 |
|---|---|---|---|---|---|
| Spirit Airlinesthin sample | 12 | 83.3% | 26 min | 0.00% | B+ |
| Southwest Airlines | 1,229 | 80.6% | 60 min | 1.38% | B |
Best ways to make this trip
The most reliable ways to fly Baltimore to Charleston
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 4 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. IAD → CHSWashington to Charleston | United Airlines | 88.7% | 89.5% | 0.86% | 8am–11am, Thu | — |
| 2. BWI → CHSBaltimore to Charleston | Southwest Airlines | 79.5% | 80.6% | 1.38% | 8am–11am, Wed (route) | — |
| 3. DCA → CHSWashington to Charleston | Republic Airways | 77.9% | 80.7% | 3.47% | 8pm–5am, Tue | — |
| 4. DCA → CHSWashington to Charleston | PSA Airlines | 65.6% | 68.6% | 4.35% | 8am–11am, Sat | — |
| 5. DCA → CHSWashington to Charleston | American Airlines | 63.6% | 65.0% | 2.19% | 8am–11am, Sat | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 28 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–8am10 flights—
- 8am–11am366 flights90.0%
- 11am–2pm250 flights85.5%
- 2pm–5pm118 flights80.3%
- 5pm–8pm334 flights75.6%
- 8pm–5am163 flights61.8%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 61.8% on time, against 90.0% for the 8am–11am 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 8am–11am window is the busiest, with 366 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 22 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.
July is the worst month at 69.9% on time, 22 points below January, the best at 92.1%. 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. October was the busiest month here, with 118 flights.
Across the week, Wednesday is the strongest day at 85.7% on time and Sunday the weakest at 76.9%. 9 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 51% of the 14,000 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.
- 51%Late-arriving aircraft
- 29%Carrier
- 16%National Airspace System
- 5%Extreme weather
51% 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 14,000 reported delay minutes here, that single category outweighs weather by 11 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 14,137 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 90.0% on time here.
Cancellations sit at 1.37% against a national 1.81%, which is ordinary. Diversions add another 0.24%.
Connections and stage length
What a delay here actually costs
5.9% 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 about an hour, which a normal layover absorbs.
At 472 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 8am–11am window matters as much as it does.
The return leg runs 81.6% on time across 1,240 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 1,241 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 CHS 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. January runs 92.1% on time and July 69.9%, a swing of 22 points. If the dates move at all, move them out of July before you think about anything else. 1,221 completed flights over 12 months sit behind that.
Common questions
BWI to CHS questions
How often is BWI to CHS 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 19.4% of the 1,241 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is BWI to CHS compared with the rest of the country?
80.6% of flights arrive on time here against a national 77.6%, 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 BWI to CHS?
The 8am–11am departure window is the strongest at 90.0% on time. The 8pm–5am window is the weakest at 61.8%, 28 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 BWI to CHS?
July is the weakest month at 69.9% on time, compared with 92.1% in January. Across the year that is 22 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
- CHS to BWI — the return legseparate record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- BWI to ATL, a related route80.6%
- ATL to CHS, a related route83.7%
- BWI to MCO, a related route75.6%
- Spirit Airlines on-time record83.3%
- Southwest Airlines on-time record80.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. BWI to CHS and CHS to BWI 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.