Population measures provide insight on the changing size and face of communities. The racial and ethnic composition of a community can offer insights in to the strengths, needs and challenges of specific groups within the community.

Westchester County has grown more diverse since 2000. The Hispanic population grew fastest, increasing by 68% from 2000 to 2016-20, followed by the Asian population (44%) and the African American population (9%). The white population decreased by 9% during this same time period but still makes up a large majority with over 598,000 residents.

Growth in Westchester County's Hispanic population was on par with the nation, outpaced the state (30%), but was slower than in Putnam (157%), Rockland (99%) and Nassau (73%) counties. Westchester County's Asian population growth was below the nation (80%), state (60%), and the counties of Nassau (121%) and Putnam (73%), but greater than Rockland (23%).

The multi-year 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).