Route reliability record
HOU→BWI
Houston to Baltimore
- Flights
- 1,457
- Period
- July 2025 to June 2026
- Distance
- 1,246 mi
- Carriers
- 1
This route sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 1,457 HOU to BWI flights, with a median arrival 1 minute early.
Best time to fly HOU to BWI: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 91.9% of the time and Tuesday flights 80.0%, against 75.4% 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
75.4%
Arrivals under 15 minutes late, of 1,432 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
1.65%
National rate is 1.81%
Best carrier
Southwest
75.4% on time across 1,457 flights
These figures cover 1,457 flights between July 2025 and June 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.
Carrier by carrier
Which airline is most reliable on HOU 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 | 1,457 | 75.4% | 48 min | 1.65% | B |
Best ways to make this trip
The most reliable ways to fly Houston 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. 4 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. IAH → IADHouston to Washington | United Airlines | 80.1% | 80.4% | 0.43% | 5am–8am, Mon | UA 1549 07:20 |
| 2. IAH → BWIHouston to Baltimore | United Airlines | 77.4% | 77.9% | 0.61% | 5am–8am, Tue | — |
| 3. IAH → BWIHouston to Baltimore | Spirit Airlines | 75.4% | 77.0% | 2.12% | 5am–8am, Thu | — |
| 4. IAH → DCAHouston to Washington | United Airlines | 74.6% | 75.2% | 0.79% | 5am–8am, Tue | UA 512 07:30 |
| 5. HOU → BWIHouston to Baltimore | Southwest Airlines | 74.2% | 75.4% | 1.65% | 5am–8am, Tue | — |
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 37 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–8am388 flights91.9%
- 8am–11am190 flights86.2%
- 11am–2pm175 flights82.6%
- 2pm–5pm230 flights67.1%
- 5pm–8pm293 flights61.2%
- 8pm–5am181 flights55.3%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 55.3% on time, against 91.9% 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 5am–8am window is the busiest, with 388 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 35 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.
Delays peak in March, when the on-time rate falls to 56.7%. January is the strongest month at 91.8%. Moving a flexible trip across that boundary buys 35 points. December was the busiest month here, with 131 flights.
Across the week, Tuesday is the strongest day at 80.0% on time and Monday the weakest at 71.1%. 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 43% of the 17,000 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.
- 43%Late-arriving aircraft
- 36%Carrier
- 16%National Airspace System
- 4%Extreme weather
- 1%Security
43% 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 17,000 reported delay minutes here, that single category outweighs weather by 12 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 16,787 reported delay minutes.
The largest share of delay minutes, 36%, 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 6,070 of the 17,000 delay minutes reported here.
Cancellations sit at 1.65% against a national 1.81%, which is ordinary. Diversions add another 0.07%.
Connections and stage length
What a delay here actually costs
5.2% 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 roughly 50 minutes, which a normal layover absorbs.
The 1,246 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 runs 76.3% on time across 1,453 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 1,457 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. January runs 91.8% on time and March 56.7%, a swing of 35 points. If the dates move at all, move them out of March before you think about anything else. 1,432 completed flights over 12 months sit behind that.
Common questions
HOU to BWI questions
How often is HOU 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 24.6% of the 1,457 flights in this analysis, against 22.4% nationally. Delayed flights are late by roughly 50 minutes on average.
How reliable is HOU to BWI compared with the rest of the country?
75.4% of flights arrive on time here against a national 77.6%, a difference of 2 points against it. That is worth a B on this site's grading scale.
What time of day has the fewest delays on HOU to BWI?
The 5am–8am departure window is the strongest at 91.9% on time. The 8pm–5am window is the weakest at 55.3%, 37 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 March delays on HOU to BWI?
March is the weakest month at 56.7% on time, compared with 91.8% in January. Across the year that is 35 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 HOU — the return legseparate record
- William P. Hobby (HOU) delay statistics
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- HOU to DAL, a related route80.9%
- ATL to BWI, a related route75.6%
- HOU to ATL, a related route79.8%
- Southwest Airlines on-time record75.4%
- 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. HOU to BWI and BWI to HOU 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.