Population measures provide insight on the changing size and face of communities. The racial and ethnic composition of a community can offer insight into its levels of diversity, which can bring with it challenges and opportunities.

Worcester County has grown more diverse since 2008-12. Its Latino population grew the fastest, 43%, from about 75,200 residents in 2008-12 to 107,200 in 2018-22. The Black or African American population increased 38%, from 32,400 to 44,700, and the Asian population grew 37%, from 32,000 to 43,900. The White population decreased 3% but still makes up 78% of the population with 671,300 residents. Worcester County's growing diversity outpaced both the state and nation.

While White residents were the largest racial group in every municipality in Worcester County in 2018-22. The cities of Worcester and Fitchburg are population centers for the Latino population, with about 50,200 (6%) and 12,700 (31%) Latino residents, respectively.

The composition of the U.S. population is becoming more racially and ethnically diverse as people of color grow in representation and will be a majority within the next two decades. Latino, Asian and multiracial groups are experiencing the largest growth with Latino's rapid increase caused largely by immigration. Latino immigrants who enter the U.S. tend to be younger and of child-bearing age.

Rate is percentage change from 2008-12. The multiyear figures are from the Census Bureau's American Community Survey. The bureau combined five years of responses to the survey to provide estimates for smaller geographic areas and increase the precision of its estimates. However, because the information came from a survey, the samples responding to the survey were not always large enough to produce reliable results, especially in small geographic areas. CGR has noted on data tables the estimates with relatively large margins of error. Estimates with three asterisks have the largest margins, plus or minus 50% or more of the estimate. Two asterisks mean plus or minus 35%-50%, and one asterisk means plus or minus 20%-35%. For all estimates, the confidence level is 90%, meaning there is 90% probability the true value (if the whole population were surveyed) would be within the margin of error (or confidence interval). The survey provides data on characteristics of the population that used to be collected only during the decennial census.

The Census Bureau asks people to identify their race (White, African-American, etc.) separate from their ethnicity (Hispanic or non-Hispanic). So the totals for these categories cannot be added together, as people show up in both a racial and ethnic group. Data for this indicator are released annually in December.