ZIP code 95503 is officially located in the state of California, primarily serving the city of Eureka. It falls under the administrative jurisdiction of Humboldt County. When planning mail delivery, logistics routing, or demographic research, 95503 operates within the Pacific Time (PT) timezone and supports the 301 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 95503 ZIP Code Tabulation Area is approximately 40,201. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $91,503.