ZIP code 92377 is located in southern California and covers a slightly less than average land area compared to other ZIP codes in the United States. Area Code Database Get all Area Codes and NXX data for North America. MightyCall can provide you a great variety of local phone numbers in Rialto,California. This is the RIALTO ZIP Code page list. mi. The City of Rialto’s Community Compliance Division provides service to the 103,000 plus residents of this community and our local business partners in the City’s twenty-two square mile geographic limits. Detailed demographic information for zip code 92376. Zip Code 92376 - Rialto CA California, USA - San Bernardino County Rialto covers 2 zip codes and is located in West region of Pacific division.