While these may not be the average incomes, these are the median incomes. Median means denoting or relating to a value or quantity lying at the midpoint of a frequency distribution of observed values or quantities, such that there is an equal probability of falling above or below it.
Therefore, median means middle.
Although not a perfect definition, you can consider this average.
The average income in Houston, Texas depends on the size of your household.
The source is the Census Bureau, IRS, and Department of Justice.
Below is the median income.
Beyond household of 4, add $9,000 per additional person.
Household of 1
$50,144
Household of 2
$65,429
Household of 3
$72,271
Household of 4
$83,960