Rialto, California
Pacific Time Zone (UTC-8) · CA · —
909
1992
San Bernardino
California
Pacific
Split
+1
840
2021
San Bernardino
California
Pacific
Overlay
About Area Codes in Rialto, California
Rialto, California is served by 2 area codes: 909, 840. When multiple area codes serve the same geographic area, it typically indicates overlay codes have been added to accommodate growing demand for phone numbers. All local calls within Rialto require 10-digit dialing. The city is in the Pacific time zone (UTC-8).
Other cities in area code 909
Frequently Asked Questions
What area code is Rialto, California?
Rialto, California uses area codes 909 and 840.
What time zone is Rialto in?
Rialto is in the Pacific time zone (UTC-8).
Do I need to dial 10 digits when calling Rialto?
Yes, all local calls in Rialto require 10-digit dialing because the area is served by multiple overlay area codes.
When was area code 909 created?
Area code 909 was established in 1992 as a geographic split from a larger area code region to serve the growing population.
What cities share area code 909 with Rialto?
Other cities sharing area code 909 with Rialto include Chino, Chino Hills, Claremont, Colton, Diamond Bar, among others.
Rialto, CA · Pacific Time Zone