[5] The city is named from the Greek expression Eureka, meaning "I have found it".

[8][9][10] An EF3 tornado struck Eureka on June 26, 2018 at 7:21 pm (daylight).

According to the United States Census Bureau, the city has a total area of 2.28 square miles (5.91 km2), all of it land.

[12] The climate in this area is characterized by hot, humid summers and generally mild to cool winters.

[13] The 2020 United States census counted 2,332 people, 1,038 households, and 568 families in Eureka.

39.4% of households consisted of individuals and 18.1% had someone living alone who was 65 years of age or older.

There were 1,410 housing units at an average density of 618.4 per square mile (238.8/km2).

39.3% of all households were made up of individuals, and 18.8% had someone living alone who was 65 years of age or older.

There were 1,561 housing units at an average density of 798.3 per square mile (308.2/km2).

38.1% of all households were made up of individuals, and 21.8% had someone living alone who was 65 years of age or older.

The community is served by Eureka USD 389 public school district.

Eureka Municipal Airport is a city-owned, public-use airport located two nautical miles (4 km) north of the central business district of Eureka.