Route profile
SAN→IAH
Flight reliability, delays and best times to fly from San Diego to Houston, 1,303 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 74% of comparable major US routes (4,598 compared)
Calculated from 5,435 flights. How this is calculated · What counts as on time
SAN → IAH arrives on time 84.4% of the time; the return trip, IAH → SAN, arrives on time 80.3% of the time, a 4.1-point gap between the two directions of the same city pair.
SAN → IAH spends 31.3 minutes on the ground on a 1,303-mile trip: 21.1 minutes from pushback to wheels-up at SAN and 10.2 minutes from touchdown to gate at IAH.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Unlike most, it barely matters what time you fly this route, a steadier spread than 93% of 4,023 comparable routes.
89.4% on time for 5–9 AM departures, against 81.5% for 12–3 PM, a narrow gap either way.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 4,023 in the comparison.
What sets this route apart
Where SAN to IAH differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SAN to IAH is at its best against routes of similar length for flights scheduled at 4 PM: 88.1% arrive on time, 18.2 points ahead of the 69.9% those routes manage at that hour. Against all other routes the gap is 17.4 points.
SAN to IAH holds up on Sundays better than routes of similar length do: 82.5% on time to their 74.6%, a 7.9 points lead. Against all other routes the gap is 7.7 points.
April is kinder to SAN to IAH than to routes of similar length: 91.0% on time against 79.2%, 11.8 points better. Against all other routes the gap is 11.1 points.
United Airlines does better on SAN to IAH than on its routes of similar length: 84.7% on time here, 81.2% there, 3.5 points apart. Against all other routes the gap is 4.8 points.
SAN to IAH against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 4 PM departures | 88.1% | routes of similar length | 69.9% | +18.2 pts | 143 here, 109,015 there |
| Weekday: Sunday | 82.5% | routes of similar length | 74.6% | +7.9 pts | 789 here, 254,326 there |
| Month: April | 91.0% | routes of similar length | 79.2% | +11.8 pts | 420 here, 145,730 there |
| Airline: United Airlines | 84.7% | routes of similar length | 81.2% | +3.5 pts | 5,230 here, 278,611 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,303 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
Why SAN → IAH flights are cancelled
July 2023 – July 2026
SAN → IAH cancelled 74 of 5,435 scheduled flights — about 1 in every 73. The reason filed most often was the airline, 55.4% of the cancellations coded on this route — about 1 in every 133 scheduled flights.
Share of cancellations
Of 74 cancelled departures carrying a reason code.
What each reason means
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
41 cancellations, 55.4% of the total.
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
25 cancellations, 33.8% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
8 cancellations, 10.8% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. With only one or two carriers on the route, the split mostly reflects how they file. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
74 coded cancellations were recorded on SAN → IAH; the section appears from 50.
When it goes wrong
July 2023 – July 2026
29 min late
against a median of 8 min early
Percentiles over 5,435 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at IAH after arriving from SAN.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 30% | High risk |
| 45 min | 15% | High risk |
| 60 min | 9.7% | Some risk |
| 90 min | 5.3% | Some risk |
| 120 min | 3.3% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.36% of the time and diverts 0.40% of the time, which a late arrival never shows up in.
Chance of missing is the share of 5,339 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 29 minutes late (90th-percentile gate arrival delay), over 5,435 operations.
Any other layover length: connection checker.
Best time to fly
SAN → IAH flights departing 5–9 AM arrived on time 89.4% of the time, against 81.5% for 12–3 PM departures, a gap of 7.9 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 91.2% on time from 359 flights
- 7 AM: 89.8% on time from 129 flights
- 8 AM: 88.5% on time from 810 flights
- 9 AM: too few flights to score
- 10 AM: 88.2% on time from 1,079 flights
- 11 AM: 74.5% on time from 320 flights
- 12 PM: 83.8% on time from 809 flights
- 1 PM: 79.1% on time from 667 flights
- 2 PM: too few flights to score
- 3 PM: 80.3% on time from 698 flights
- 4 PM: 88.1% on time from 144 flights
- 5 PM: 85.8% on time from 318 flights
- 6 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why SAN → IAH runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for SAN → IAH. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on SAN → IAH, at 46.6%: flights here mostly leave late because the plane came in late, though departure time makes little difference here: the best and worst windows are 8 points apart.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| United Airlines | 5,318 | 84.7% | 1.30% | -8 min | 5.3% |
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Sunday the least, a gap of 5.6 percentage points.
By month
- Jan: 88.5%
- Feb: 91.4%
- Mar: 87.1%
- Apr: 91.0%
- May: 82.2%
- Jun: 78.9%
- Jul: 73.7%
- Aug: 81.6%
- Sep: 89.2%
- Oct: 87.0%
- Nov: 87.1%
- Dec: 82.2%
July is historically the weakest month and February the strongest, a spread of 17.7 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 73.3% from 152 flights
- August 2023: 85.2% from 155 flights
- September 2023: 91.5% from 168 flights
- October 2023: 89.1% from 183 flights
- November 2023: 91.0% from 145 flights
- December 2023: 90.5% from 148 flights
- January 2024: 89.5% from 131 flights
- February 2024: too few flights to score (113)
- March 2024: 90.5% from 137 flights
- April 2024: 91.4% from 141 flights
- May 2024: 80.4% from 173 flights
- June 2024: 81.0% from 180 flights
- July 2024: 70.8% from 185 flights
- August 2024: 81.0% from 181 flights
- September 2024: 87.4% from 143 flights
- October 2024: 81.5% from 147 flights
- November 2024: 91.9% from 148 flights
- December 2024: 69.7% from 148 flights
- January 2025: 87.7% from 129 flights
- February 2025: 89.3% from 122 flights
- March 2025: 90.8% from 142 flights
- April 2025: 89.3% from 141 flights
- May 2025: 81.0% from 145 flights
- June 2025: 75.4% from 141 flights
- July 2025: 75.7% from 141 flights
- August 2025: 78.4% from 141 flights
- September 2025: 88.2% from 137 flights
- October 2025: 89.8% from 147 flights
- November 2025: 78.2% from 142 flights
- December 2025: 86.2% from 145 flights
- January 2026: 88.3% from 128 flights
- February 2026: 92.1% from 127 flights
- March 2026: 80.5% from 152 flights
- April 2026: 92.1% from 142 flights
- May 2026: 85.2% from 149 flights
- June 2026: 79.6% from 142 flights
- July 2026: 75.5% from 144 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 84.4% against 83.2% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 5,435 SAN → IAH flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed