ACS reports data based on the four categories of English-speaking ability: “very well,” “well,” “not well,” and “not at all.” The City defines the LD population as individuals who speak English less than “very well,” which is consistent with US DOT guidelines.

As shown in Table 1 below, approximately 20.4% of residents in the City of San Rafael are considered Linguistically Diverse (LD) persons, those who speak English less than "very well." The largest share of LD persons speak Spanish (16.3% of the community), followed by Other and Unspecified languages (1.3%), Other Indo-European languages (0.6%), Vietnamese (0.4%), and Tagalog, including Filipino (0.4%). The table shows that Spanish is by far the dominant non-English language, representing 28.3% of the total population 5 years and over, and accounting for approximately 80% of all LD persons in San Rafael. No individual non-Spanish-language group accounts for more than 1.3% of the total community population with limited English proficiency.

Source: U.S. Census Bureau. "Language Spoken at Home for the Population 5 Years and Over." American Community Survey, ACS 5-Year Estimates Detailed Tables, Table C16001, 2024. Accessed March 13, 2026.