Route reliability record
SAN→BWI
San Diego to Baltimore
- Flights
- 1,182
- Period
- September 2025 to August 2026
- Distance
- 2,295 mi
- Carriers
- 1
This route lands a B, level with the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about 45 minutes on average. That rests on 1,182 SAN to BWI flights, with a median arrival 1 minute early.
Best time to fly SAN to BWI: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 90.1% of the time and Saturday flights 88.2%, against 76.6% for the route overall.
The US average over the same twelve months is 77.3%, 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
76.6%
Arrivals under 15 minutes late, of 1,154 completed flights
Avg delay
45 min
Across delayed arrivals only, not all flights
Cancelled
1.69%
National rate is 1.89%
Best carrier
Southwest
76.6% on time across 1,182 flights
These figures cover 1,182 flights between September 2025 and August 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
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Carrier by carrier
Which airline is most reliable on SAN to BWI
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 |
|---|---|---|---|---|---|
| Southwest Airlines | 1,182 | 76.6% | 45 min | 1.69% | B |
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Best ways to make this trip
The most reliable ways to fly San Diego to Baltimore
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. 1 of the top 2 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SAN → IADSan Diego to Washington | United Airlines | 87.3% | 88.0% | 0.77% | 8am–11am, Tue | UA 1071 08:00 |
| 2. SAN → BWISan Diego to Baltimore | Southwest Airlines | 75.3% | 76.6% | 1.69% | 5am–8am, 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 39 points, against half a point between the best and worst carrier.
- 5am–8am340 flights90.1%
- 8am–11am35 flights66.7%
- 11am–2pm339 flights60.9%
- 2pm–5pm103 flights51.5%
- 5pm–8pm—
- 8pm–5am365 flights86.4%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 90.1% of the time, against 51.5% for the afternoon window. That is 39 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 365 flights scheduled in it.
Explore
Filter SAN to BWI by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On SAN to BWI, the best departure window is 5am–8am at 90.1% on time and the worst is 2pm–5pm at 51.5%, a wide gap of 38.6 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am90.1%
- 8–11am66.7%
- 11am–2pm60.9%
- 2–5pm51.5%
- 5–8pm—
- 8pm–5am86.4%
best all US flightsScale 45% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 32 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 58.4% on time, 32 points below September, the best at 90.1%. 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. May was the busiest month here, with 106 flights.
Across the week, Saturday is the strongest day at 88.2% on time and Thursday the weakest at 71.0%, a spread of 17 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 53% of the 12,000 delay minutes carriers reported here, and the remaining four split what is left.
- 53%Late-arriving aircraft
- 29%Carrier
- 17%National Airspace System
- 1%Security
- 0%Extreme weather
53% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 12,000 reported delay minutes here, that single category outweighs weather by 53 to one. The split is drawn from 12,169 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 90.1% on time here.
Cancellations sit at 1.69% against a national 1.89%, which is ordinary. Diversions add another 0.68%.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 4.4% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
At 2,295 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 72.9% on time across 1,165 flights, 4 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 4 points of difference.
The sample behind these figures is 1,182 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 BWI 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. September runs 90.1% on time and July 58.4%, a swing of 32 points. If the dates move at all, move them out of July before you think about anything else. 1,154 completed flights over 12 months sit behind that.
Common questions
SAN to BWI questions
How often is SAN to BWI delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.4% of the 1,182 flights in this analysis, against 22.7% nationally. Delayed flights are late by about 45 minutes on average.
How reliable is SAN to BWI compared with the rest of the country?
76.6% of flights arrive on time here against a national 77.3%, a difference of half a point against it. That is worth a B on this site's grading scale.
What time of day has the fewest delays on SAN to BWI?
The 5am–8am departure window is the strongest at 90.1% on time. The 2pm–5pm window is the weakest at 51.5%, 39 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 SAN to BWI?
July is the weakest month at 58.4% on time, compared with 90.1% in September. Across the year that is 32 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
- BWI to SAN — the return legseparate record
- San Diego International (SAN) delay statistics
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- SAN to SFO, a related route59.5%
- ATL to BWI, a related route75.2%
- SAN to DEN, a related route78.4%
- Southwest Airlines on-time record76.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. SAN to BWI and BWI to SAN 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.