The city's motto is "Oasis in the Sun".
Avenal is a small city of approximately 16,737 people, including prison inmates. Avenal owes its origin to the discovery of oil on 4 October 1928, in the adjacent Kettleman Hills. Avenal was the site of a "tent city" as the boom started, but foresight made the boom orderly, so that by 1940 Avenal was the second largest town in Kings County with a population of 4,600.
Growth continues today to include a more diversified economy based on oil, agriculture, and the service industry. In 1978, Avenal citizens voted to incorporate and improve the quality of life for all Avenal residents. The presence of the Avenal State Prison helps this rural community maintain economic stability, especially as the once-productive Kettleman North Dome Oil Field reaches exhaustion (less than one-half of one percent of its original oil remains).
As of the census of 2000, there were 15,689 people, 1,928 households, and 1,640 families residing in the city. The population density was 767.3 people per square mile (296.3/km²). There were 2,061 housing units at an average density of 107.8/sq mi (41.6/km²). The racial makeup of the city was 35.84% White, 12.61% Black or African American, 0.95% Native American, 0.39% Asian, 0.05% Pacific Islander, 47.38% from other races, and 2.79% from two or more races. 65.88% of the population were Hispanic or Latino of any race.
There were 1,928 households out of which 60.2% had children under the age of 18 living with them, 58.5% were married couples living together, 16.8% had a female householder with no husband present, and 14.9% were non-families. 11.3% of all households were made up of individuals and 4.7% had someone living alone who was 65 years of age or older. The average household size was 4.14 and the average family size was 4.30.
In the city the population was spread out with 21.9% under the age of 18, 13.5% from 18 to 24, 46.5% from 25 to 44, 15.0% from 45 to 64, and 3.3% who were 65 years of age or older. The median age was 31 years. For every 100 females there were 289.7 males. For every 100 females age 18 and over, there were 403.5 males.
The median income for a household in the city was $29,710, and the median income for a family was $28,019. Males had a median income of $30,802 versus $20,852 for females. The per capita income for the city was $14,090. About 28.3% of families and 30.7% of the population were below the poverty line, including 34.4% of those under age 18 and 5.0% of those age 65 or over.