Route reliability record
SAN→HOU
San Diego to Houston
- Flights
- 961
- Period
- July 2025 to June 2026
- Distance
- 1,313 mi
- Carriers
- 1
This route sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.6%. The late ones land about 45 minutes behind schedule. That rests on 961 SAN to HOU flights, with a median arrival right on schedule.
Best time to fly SAN to HOU: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 89.7% of the time and Saturday flights 84.4%, against 71.4% for the route overall.
The national on-time rate over the same period is 77.6%, so this route runs 6 points behind the country as a whole. Across a thousand flights that is about 62 extra late arrivals.
Key figures
On time
71.4%
Arrivals under 15 minutes late, of 955 completed flights
Avg delay
45 min
Across delayed arrivals only, not all flights
Cancelled
0.42%
National rate is 1.81%
Best carrier
Southwest
71.4% on time across 961 flights
These figures cover 961 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 SAN to HOU
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 | 961 | 71.4% | 45 min | 0.42% | C+ |
Best ways to make this trip
The most reliable ways to fly San Diego to Houston
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 → IAHSan Diego to Houston | United Airlines | 84.1% | 84.5% | 0.53% | 5am–8am, Tue | UA 2237 11:58 |
| 2. SAN → HOUSan Diego to Houston | Southwest Airlines | 71.1% | 71.4% | 0.42% | 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 40 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–8am317 flights88.8%
- 8am–11am39 flights89.7%
- 11am–2pm211 flights70.0%
- 2pm–5pm131 flights49.6%
- 5pm–8pm191 flights60.5%
- 8pm–5am72 flights58.3%
Scale runs 40% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 89.7% of the time, against 49.6% for the afternoon window. That is 40 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 317 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 36 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.
September is the best month on the calendar at 90.0% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. December was the busiest month here, with 91 flights.
Across the week, Saturday is the strongest day at 84.4% on time and Thursday the weakest at 61.5%. 23 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 57% of the 12,000 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.
- 57%Late-arriving aircraft
- 28%Carrier
- 14%National Airspace System
- 1%Security
57% 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 12,000 reported delay minutes here, that single category outweighs weather by 57 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 12,401 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 89.7% on time here.
Cancellations are rare at 0.42%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here actually costs
6.1% 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 45 minutes, which a normal layover absorbs.
The 1,313 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 76.3% on time across 961 flights, 5 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 5 points of difference.
One caution: this is a thin sample. 961 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.
Work out the risk of missing a connection in HOU after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 961 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 71.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 955 completed flights over 12 months sit behind that.
Common questions
SAN to HOU questions
How often is SAN to HOU delayed?
Roughly one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 28.6% of the 961 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 45 minutes on average.
How reliable is SAN to HOU compared with the rest of the country?
71.4% of flights arrive on time here against a national 77.6%, a difference of 6 points against it. That is worth a C+ on this site's grading scale.
What time of day has the fewest delays on SAN to HOU?
The 8am–11am departure window is the strongest at 89.7% on time. The 2pm–5pm window is the weakest at 49.6%, 40 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 SAN to HOU?
March is the weakest month at 54.2% on time, compared with 90.0% in September. Across the year that is 36 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
- HOU to SAN — the return legseparate record
- San Diego International (SAN) delay statistics
- William P. Hobby (HOU) delay statistics
- SAN to SFO, a related route65.0%
- DAL to HOU, a related route74.1%
- SAN to DEN, a related route79.2%
- Southwest Airlines on-time record71.4%
- 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. SAN to HOU and HOU 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.