Area code 858 was brought into effect on June 12, 1999. 858 was split from the parent 619 area code.
Counties in Area Code 858
- San Diego.
Most Populous Cities in Area Code 858
|City||County||City Population||Time Zone|
|La Jolla||San Diego||48,016||PST|
|Del Mar||San Diego||13,501||PST|
|Solana Beach||San Diego||12,374||PST|
Note: The above list is based off of the top 25 most populous cities in the area code as per 2012 United States Census Bureau estimates.
View all United States Area Codes.