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DelayAtlas

Route reliability record

SAN→HOU

San Diego to Houston

Flights
985
Period
September 2025 to August 2026
Distance
1,313 mi
Carriers
1
C+GRADE

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, 8 points worse than the national rate of 77.3%. The late ones land about 45 minutes behind schedule. That rests on 985 SAN to HOU flights, with a median arrival 1 minute late.

Best time to fly SAN to HOU: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 90.2% of the time and Saturday flights 80.7%, against 69.6% for the route overall.

The national on-time rate over the same period is 77.3%, so this route runs 8 points behind the country as a whole. Across a thousand flights that is about 77 extra late arrivals.

Key figures

On time

69.6%

Arrivals under 15 minutes late, of 978 completed flights

Avg delay

45 min

Across delayed arrivals only, not all flights

Cancelled

0.41%

National rate is 1.89%

Best carrier

Southwest

69.6% on time across 985 flights

These figures cover 985 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 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.

On-time performance by carrier on SAN to HOU
AirlineFlightsOn timeAvg delayCancelledGrade
Southwest Airlines98569.6%45 min0.41%C+

Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

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.

Most reliable ways to fly from SAN to HOU
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. SAN → IAHSan Diego to HoustonUnited Airlines83.6%83.9%0.30%5am–8am, TueUA 2237 11:58
2. SAN → HOUSan Diego to HoustonSouthwest Airlines69.3%69.6%0.41%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.

Plan this trip by month, day and time

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 41 points, against half a point between the best and worst carrier.

  • 5am–8am310 flights89.5%
  • 8am–11am41 flights90.2%
  • 11am–2pm204 flights64.0%
  • 2pm–5pm134 flights49.3%
  • 5pm–8pm204 flights59.6%
  • 8pm–5am92 flights58.7%

Scale runs 40% to 95%.

Book the morning departure. Flights leaving between 8am–11am arrive on time 90.2% of the time, against 49.3% for the afternoon window. That is 41 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 310 flights scheduled in it.

Explore

Filter SAN to HOU 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 HOU, the best departure window is 8am–11am at 90.2% on time and the worst is 2pm–5pm at 49.3%, a wide gap of 40.9 points. All US flights leaving 8am–11am ran 83.9%.

  • 5–8am89.5%
  • 8–11am90.2%
  • 11am–2pm64.0%
  • 2–5pm49.3%
  • 5–8pm59.6%
  • 8pm–5am58.7%

best all US flightsScale 40% to 95%.

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.

On-time rate by calendar month81J80F54M79A56M61J61J57A90S71O76N79D
Darker means more delays. Figures are on-time percentages.September best, March worst

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 80.7% on time and Friday the weakest at 63.9%, a spread of 17 points.

On-time rate by day of the week69.8Mon75.4Tue68.1Wed66.7Thu63.9Fri80.7Sat65.7Sun
Monday: 69.8 percent on time. Tuesday: 75.4 percent on time. Wednesday: 68.1 percent on time. Thursday: 66.7 percent on time. Friday: 63.9 percent on time. Saturday: 80.7 percent on time. Sunday: 65.7 percent on time

Delay causes

Why this route gets delayed

Late-arriving aircraft accounts for 59% of the 13,000 delay minutes carriers reported here, and the remaining four split what is left.

  • Late-arriving aircraft
    59%
  • Carrier
    29%
  • National Airspace System
    11%
  • Security
    1%

59% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 13,000 reported delay minutes here, that single category outweighs weather by 59 to one. The split is drawn from 13,261 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 90.2% on time here.

Cancellations are rare at 0.41%, below the national 1.89% 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

6.6% of arrivals land an hour or more late, close to the national 8.3%, so 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.

The return leg is a different operation and performs like one: it runs 73.9% on time across 985 flights, 4 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 4 points of difference.

One caution: this is a thin sample. 985 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. 985 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 69.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 978 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 30.4% of the 985 flights in this analysis, against 22.7% nationally. Delayed flights are late by about 45 minutes on average.

How reliable is SAN to HOU compared with the rest of the country?

69.6% of flights arrive on time here against a national 77.3%, a difference of 8 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 90.2% on time. The 2pm–5pm window is the weakest at 49.3%, 41 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

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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.